V4L/DVB (9036): uvcvideo: Fix control cache access when setting composite auto-update controls

Auto-update controls are never marked is loaded to prevent uvc_get_ctrl from
loading the control value from the cache. When setting a composite (mapped to
several V4L2 controls) auto-update UVC control, the driver updates the control
cache value before processing each V4L2 control, overwriting the previously
set V4L2 control.

This fixes the problem by marking all controls as loaded in uvc_set_ctrl
regardless of their type and resetting the loaded flag in uvc_commit_ctrl for
auto-update controls.

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