V4L/DVB (12184): uvcvideo: Use class-specific descriptor types from usb/ch9.h

uvcvideo.h redefines class-specific descriptor types already present in
usb/ch9.h. Remove the duplicated definitions and use the ones from usb/ch9.h.

Signed-off-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>