media: vicodec: Use _BITUL() macro in UAPI headers

Replace BIT() in v4l2's UPAI header with _BITUL(). BIT() is not defined
in the UAPI headers and its usage may cause userspace build errors.

Fixes: 206bc0f6

 ("media: vicodec: mark the stateless FWHT API as stable")
Signed-off-by: Joe Richey <joerichey@google.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>