va: add new ABGR/XBGR fourcc codes.
va: add new ABGR/XBGR fourcc codes.

Add VA_FOURCC_ABGR and its companion VA_FOURCC_XBGR definition. This
represents a packed RGB format with 32 bpp, i.e. 8-bit per component.
The components order in memory is A B G R.

Signed-off-by: Victor Ying <6d7ab2e6d20ba0451a6b9e51407f8974fe129366@intel.com>
Signed-off-by: Gwenole Beauchesne <729713629d9640cc095f1c77c692e1881f8093c4@intel.com>

01org/libva-cros,chenxianqin/vaapi-libva,zzhhui/libva,gbeauchesne/libva,zzhhui/libva,chenxianqin/vaapi-libva,01org/iotg-lin-gfx-libva,01org/iotg-lin-gfx-libva,zzhhui/libva,01org/libva-cros,pma1/libva,01org/libva-cros,gbeauchesne/libva,01org/iotg-lin-gfx-libva,pma1/libva,chenxianqin/vaapi-libva,pma1/libva,gbeauchesne/libva