media: v4l2-common: add RGB565 and RGB55 to v4l2_format_info

Add RGB565 and RGB555 to the v4l2_format_info table.

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