media: amphion: vdec check format in enum_fmt

vdec check the pixel format is supported by vpu,
or is it disabled.
And don't report it if the result is false

Signed-off-by: Ming Qian <ming.qian@nxp.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>