common_use_cases: add description of SOC_FAMILY
common_use_cases: add description of SOC_FAMILY

* Added a description of the SOC_FAMILY variable that
  can be set in the machine configuration files.

Signed-off-by: Chase Maupin <874d7d4fa211492c1868f6a91442712d37040f21@ti.com>
Acked-by: Paul Menzel <acd6d3b156327487a919475da61b8867f1e8b249@users.sourceforge.net>
Acked-by: Frans Meulenbroeks <6def945a6cdf470073fde46d27fb7849dda40aca@gmail.com>
Acked-by: Denys Dmytriyenko <e7d361c7f6c045f0c4fa54d2afc4a237f30bc767@denix.org>
Signed-off-by: Denys Dmytriyenko <e7d361c7f6c045f0c4fa54d2afc4a237f30bc767@denix.org>

trini/openembedded,rascalmicro/openembedded-rascal,dellysunnymtech/sakoman-oe,dellysunnymtech/sakoman-oe,nx111/openembeded_openpli2.1_nx111,giobauermeister/openembedded,Martix/Eonos,hulifox008/openembedded,BlackPole/bp-openembedded,openembedded/openembedded,yyli/overo-oe,scottellis/overo-oe,openembedded/openembedded,giobauermeister/openembedded,John-NY/overo-oe,libo/openembedded,hulifox008/openembedded,giobauermeister/openembedded,JamesAng/oe,sampov2/audio-openembedded,buglabs/oe-buglabs,dave-billin/overo-ui-moos-auv,JamesAng/goe,dellysunnymtech/sakoman-oe,sutajiokousagi/openembedded,openembedded/openembedded,dave-billin/overo-ui-moos-auv,sentient-energy/emsw-oe-mirror,yyli/overo-oe,dave-billin/overo-ui-moos-auv,openembedded/openembedded,sampov2/audio-openembedded,xifengchuo/openembedded,dellysunnymtech/sakoman-oe,mrchapp/arago-oe-dev,JamesAng/goe,BlackPole/bp-openembedded,dellysunnymtech/sakoman-oe,thebohemian/openembedded,sledz/oe,sledz/oe,hulifox008/openembedded,xifengchuo/openembedded,Martix/Eonos,scottellis/overo-oe,anguslees/openembedded-android,sutajiokousagi/openembedded,xifengchuo/openembedded,libo/openembedded,hulifox008/openembedded,libo/openembedded,dave-billin/overo-ui-moos-auv,SIFTeam/openembedded,sutajiokousagi/openembedded,sampov2/audio-openembedded,buglabs/oe-buglabs,nx111/openembeded_openpli2.1_nx111,thebohemian/openembedded,SIFTeam/openembedded,hulifox008/openembedded,yyli/overo-oe,thebohemian/openembedded,sutajiokousagi/openembedded,JamesAng/oe,libo/openembedded,openpli-arm/openembedded,yyli/overo-oe,giobauermeister/openembedded,Martix/Eonos,sampov2/audio-openembedded,sampov2/audio-openembedded,nx111/openembeded_openpli2.1_nx111,sentient-energy/emsw-oe-mirror,rascalmicro/openembedded-rascal,Martix/Eonos,scottellis/overo-oe,giobauermeister/openembedded,libo/openembedded,sentient-energy/emsw-oe-mirror,nx111/openembeded_openpli2.1_nx111,BlackPole/bp-openembedded,thebohemian/openembedded,giobauermeister/openembedded,yyli/overo-oe,rascalmicro/openembedded-rascal,sutajiokousagi/openembedded,buglabs/oe-buglabs,JamesAng/oe,thebohemian/openembedded,SIFTeam/openembedded,nx111/openembeded_openpli2.1_nx111,buglabs/oe-buglabs,John-NY/overo-oe,giobauermeister/openembedded,mrchapp/arago-oe-dev,openpli-arm/openembedded,sledz/oe,sampov2/audio-openembedded,Martix/Eonos,xifengchuo/openembedded,dave-billin/overo-ui-moos-auv,trini/openembedded,scottellis/overo-oe,openpli-arm/openembedded,openembedded/openembedded,yyli/overo-oe,thebohemian/openembedded,thebohemian/openembedded,hulifox008/openembedded,mrchapp/arago-oe-dev,sentient-energy/emsw-oe-mirror,openpli-arm/openembedded,trini/openembedded,SIFTeam/openembedded,openembedded/openembedded,yyli/overo-oe,giobauermeister/openembedded,xifengchuo/openembedded,mrchapp/arago-oe-dev,dave-billin/overo-ui-moos-auv,BlackPole/bp-openembedded,sledz/oe,openembedded/openembedded,trini/openembedded,JamesAng/goe,rascalmicro/openembedded-rascal,John-NY/overo-oe,sledz/oe,openembedded/openembedded,SIFTeam/openembedded,buglabs/oe-buglabs,openpli-arm/openembedded,trini/openembedded,nx111/openembeded_openpli2.1_nx111,Martix/Eonos,anguslees/openembedded-android,JamesAng/oe,sentient-energy/emsw-oe-mirror,JamesAng/goe,nx111/openembeded_openpli2.1_nx111,buglabs/oe-buglabs,xifengchuo/openembedded,BlackPole/bp-openembedded,John-NY/overo-oe,anguslees/openembedded-android,libo/openembedded,giobauermeister/openembedded,sledz/oe,SIFTeam/openembedded,sentient-energy/emsw-oe-mirror,trini/openembedded,BlackPole/bp-openembedded,anguslees/openembedded-android,dellysunnymtech/sakoman-oe,hulifox008/openembedded,scottellis/overo-oe,JamesAng/oe,JamesAng/goe,openpli-arm/openembedded,Martix/Eonos,nx111/openembeded_openpli2.1_nx111,buglabs/oe-buglabs,openembedded/openembedded,sutajiokousagi/openembedded,trini/openembedded,John-NY/overo-oe,scottellis/overo-oe,xifengchuo/openembedded,openembedded/openembedded,dave-billin/overo-ui-moos-auv,rascalmicro/openembedded-rascal,JamesAng/oe,sampov2/audio-openembedded,SIFTeam/openembedded,rascalmicro/openembedded-rascal,mrchapp/arago-oe-dev,xifengchuo/openembedded,rascalmicro/openembedded-rascal,yyli/overo-oe,libo/openembedded,JamesAng/goe,anguslees/openembedded-android,JamesAng/oe,openembedded/openembedded,dellysunnymtech/sakoman-oe,mrchapp/arago-oe-dev,sentient-energy/emsw-oe-mirror,sledz/oe,xifengchuo/openembedded,openpli-arm/openembedded,dellysunnymtech/sakoman-oe,dellysunnymtech/sakoman-oe,rascalmicro/openembedded-rascal,anguslees/openembedded-android,anguslees/openembedded-android,buglabs/oe-buglabs,mrchapp/arago-oe-dev,John-NY/overo-oe,sutajiokousagi/openembedded,BlackPole/bp-openembedded,scottellis/overo-oe,JamesAng/goe,John-NY/overo-oe