mm-video-v4l2: vdec: Use client defaults if bitstream aspects are unspecified

Return client-supplied-default values for color aspects if the
bitstream has unspecified values rather than enumerating "Unspecified".

Also, default to 601 (instead of 601-FR) in case colorspace is
unknown.

Bug: 29189938
Change-Id: Icbfd95a81152275a16f7f00b47973e76e7853569
1 file changed