at91sam9g20ek: enable at91bootstrap and u-boot in EXTRA_IMAGEDEPS
at91sam9g20ek: enable at91bootstrap and u-boot in EXTRA_IMAGEDEPS

The at91sam9* boards aren't really usefull w/o both bootloaders.
Reenable them for default build of at91sam9g20ek board images.

Signed-off-by: Dmitry Eremin-Solenikov <b6edad08270b2e4ffbcb0879e25a0e29a48c5275@gmail.com>

BlackPole/bp-openembedded,dellysunnymtech/sakoman-oe,crystalfontz/openembedded,thebohemian/openembedded,demsey/openenigma2,demsey/openembedded,demsey/openenigma2,rascalmicro/openembedded-rascal,mrchapp/arago-oe-dev,yyli/overo-oe,JrCs/opendreambox,rascalmicro/openembedded-rascal,mrchapp/arago-oe-dev,yyli/overo-oe,JamesAng/oe,BlackPole/bp-openembedded,sutajiokousagi/openembedded,buglabs/oe-buglabs,bticino/openembedded,sentient-energy/emsw-oe-mirror,xifengchuo/openembedded,sutajiokousagi/openembedded,anguslees/openembedded-android,trini/openembedded,JamesAng/oe,giobauermeister/openembedded,John-NY/overo-oe,Martix/Eonos,dave-billin/overo-ui-moos-auv,xifengchuo/openembedded,openembedded/openembedded,sutajiokousagi/openembedded,SIFTeam/openembedded,BlackPole/bp-openembedded,nzjrs/overo-openembedded,popazerty/openembedded-cuberevo,nzjrs/overo-openembedded,SIFTeam/openembedded,JamesAng/oe,buglabs/oe-buglabs,sledz/oe,YtvwlD/od-oe,anguslees/openembedded-android,John-NY/overo-oe,JamesAng/oe,JamesAng/goe,hulifox008/openembedded,demsey/openembedded,rascalmicro/openembedded-rascal,rascalmicro/openembedded-rascal,anguslees/openembedded-android,JamesAng/oe,YtvwlD/od-oe,sentient-energy/emsw-oe-mirror,xifengchuo/openembedded,YtvwlD/od-oe,John-NY/overo-oe,openpli-arm/openembedded,yyli/overo-oe,nzjrs/overo-openembedded,openpli-arm/openembedded,thebohemian/openembedded,buglabs/oe-buglabs,dellysunnymtech/sakoman-oe,libo/openembedded,John-NY/overo-oe,mrchapp/arago-oe-dev,popazerty/openembedded-cuberevo,bticino/openembedded,openpli-arm/openembedded,demsey/openenigma2,crystalfontz/openembedded,sledz/oe,giobauermeister/openembedded,philb/pbcl-oe-2010,demsey/openenigma2,BlackPole/bp-openembedded,openembedded/openembedded,hulifox008/openembedded,philb/pbcl-oe-2010,anguslees/openembedded-android,popazerty/openembedded-cuberevo,giobauermeister/openembedded,philb/pbcl-oe-2010,trini/openembedded,giobauermeister/openembedded,scottellis/overo-oe,crystalfontz/openembedded,JrCs/opendreambox,bticino/openembedded,dave-billin/overo-ui-moos-auv,sledz/oe,dave-billin/overo-ui-moos-auv,libo/openembedded,giobauermeister/openembedded,buglabs/oe-buglabs,giobauermeister/openembedded,SIFTeam/openembedded,nx111/openembeded_openpli2.1_nx111,JamesAng/goe,yyli/overo-oe,openpli-arm/openembedded,JamesAng/oe,dellysunnymtech/sakoman-oe,openembedded/openembedded,sampov2/audio-openembedded,philb/pbcl-oe-2010,JamesAng/goe,dellysunnymtech/sakoman-oe,openembedded/openembedded,demsey/openenigma2,nx111/openembeded_openpli2.1_nx111,libo/openembedded,Martix/Eonos,YtvwlD/od-oe,openembedded/openembedded,BlackPole/bp-openembedded,crystalfontz/openembedded,giobauermeister/openembedded,yyli/overo-oe,sampov2/audio-openembedded,YtvwlD/od-oe,rascalmicro/openembedded-rascal,sutajiokousagi/openembedded,JrCs/opendreambox,JamesAng/oe,John-NY/overo-oe,mrchapp/arago-oe-dev,nzjrs/overo-openembedded,JrCs/opendreambox,Martix/Eonos,dave-billin/overo-ui-moos-auv,demsey/openembedded,anguslees/openembedded-android,sentient-energy/emsw-oe-mirror,thebohemian/openembedded,bticino/openembedded,anguslees/openembedded-android,xifengchuo/openembedded,sampov2/audio-openembedded,openpli-arm/openembedded,demsey/openembedded,JamesAng/goe,dave-billin/overo-ui-moos-auv,philb/pbcl-oe-2010,JamesAng/goe,JamesAng/goe,mrchapp/arago-oe-dev,crystalfontz/openembedded,anguslees/openembedded-android,nx111/openembeded_openpli2.1_nx111,xifengchuo/openembedded,JrCs/opendreambox,scottellis/overo-oe,xifengchuo/openembedded,yyli/overo-oe,BlackPole/bp-openembedded,trini/openembedded,SIFTeam/openembedded,philb/pbcl-oe-2010,crystalfontz/openembedded,scottellis/overo-oe,yyli/overo-oe,sledz/oe,sutajiokousagi/openembedded,nx111/openembeded_openpli2.1_nx111,BlackPole/bp-openembedded,buglabs/oe-buglabs,dellysunnymtech/sakoman-oe,mrchapp/arago-oe-dev,dellysunnymtech/sakoman-oe,thebohemian/openembedded,scottellis/overo-oe,crystalfontz/openembedded,bticino/openembedded,openembedded/openembedded,dave-billin/overo-ui-moos-auv,libo/openembedded,hulifox008/openembedded,demsey/openembedded,giobauermeister/openembedded,sentient-energy/emsw-oe-mirror,thebohemian/openembedded,openembedded/openembedded,popazerty/openembedded-cuberevo,sampov2/audio-openembedded,dellysunnymtech/sakoman-oe,trini/openembedded,rascalmicro/openembedded-rascal,SIFTeam/openembedded,nzjrs/overo-openembedded,sledz/oe,sampov2/audio-openembedded,libo/openembedded,scottellis/overo-oe,trini/openembedded,JrCs/opendreambox,popazerty/openembedded-cuberevo,thebohemian/openembedded,buglabs/oe-buglabs,sutajiokousagi/openembedded,SIFTeam/openembedded,John-NY/overo-oe,nx111/openembeded_openpli2.1_nx111,mrchapp/arago-oe-dev,openembedded/openembedded,thebohemian/openembedded,popazerty/openembedded-cuberevo,demsey/openenigma2,popazerty/openembedded-cuberevo,Martix/Eonos,scottellis/overo-oe,hulifox008/openembedded,giobauermeister/openembedded,openpli-arm/openembedded,rascalmicro/openembedded-rascal,JrCs/opendreambox,hulifox008/openembedded,sampov2/audio-openembedded,hulifox008/openembedded,buglabs/oe-buglabs,nzjrs/overo-openembedded,sledz/oe,demsey/openembedded,libo/openembedded,demsey/openenigma2,YtvwlD/od-oe,yyli/overo-oe,rascalmicro/openembedded-rascal,Martix/Eonos,JrCs/opendreambox,openembedded/openembedded,xifengchuo/openembedded,buglabs/oe-buglabs,popazerty/openembedded-cuberevo,bticino/openembedded,scottellis/overo-oe,Martix/Eonos,nx111/openembeded_openpli2.1_nx111,xifengchuo/openembedded,Martix/Eonos,sentient-energy/emsw-oe-mirror,dellysunnymtech/sakoman-oe,openembedded/openembedded,sentient-energy/emsw-oe-mirror,openpli-arm/openembedded,sampov2/audio-openembedded,YtvwlD/od-oe,demsey/openembedded,trini/openembedded,dave-billin/overo-ui-moos-auv,libo/openembedded,trini/openembedded,bticino/openembedded,nx111/openembeded_openpli2.1_nx111,sutajiokousagi/openembedded,nx111/openembeded_openpli2.1_nx111,hulifox008/openembedded,SIFTeam/openembedded,JrCs/opendreambox,philb/pbcl-oe-2010,John-NY/overo-oe,YtvwlD/od-oe,openembedded/openembedded,xifengchuo/openembedded,nzjrs/overo-openembedded,sledz/oe,sentient-energy/emsw-oe-mirror,JamesAng/goe,dellysunnymtech/sakoman-oe