media: v4l2-tpg: add support for new pixelformats

Several new variations of RGB444, RGB555 and RGB32 were
added. Add support for these.

This is the list of new pixelformats:

V4L2_PIX_FMT_RGBX444
V4L2_PIX_FMT_RGBA444
V4L2_PIX_FMT_XBGR444
V4L2_PIX_FMT_ABGR444
V4L2_PIX_FMT_BGRX444
V4L2_PIX_FMT_BGRA444
V4L2_PIX_FMT_RGBX555
V4L2_PIX_FMT_RGBA555
V4L2_PIX_FMT_XBGR555
V4L2_PIX_FMT_ABGR555
V4L2_PIX_FMT_BGRX555
V4L2_PIX_FMT_BGRA555
V4L2_PIX_FMT_RGBX32
V4L2_PIX_FMT_BGRX32
V4L2_PIX_FMT_RGBA32
V4L2_PIX_FMT_BGRA32

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>