media: uvcvideo: Use internal kernel integer types

Replace the __[su]{8,16,32} variant of integer types with the
non-underscored types as the code is internal to the driver, not exposed
to userspace.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>