va: Add new color standard types to VPP

The four new color standards are:
sRGB     full range RGB [0,255]
stRGB    limited range RGB [16,235]
xvYCC601 extended-gamut YCC upwardly compatible with BT.601
xvYCC709 extended-gamut YCC upwardly compatible with BT.709

Signed-off-by: Oscar Mateo <oscar.mateo@intel.com>