media: pvrusb2: replace pvr2_v4l2_ioctl by video_ioctl2

This driver is the only V4L driver that does not set unlocked_ioctl
to video_ioctl2.

The only thing that pvr2_v4l2_ioctl does besides calling video_ioctl2
is calling pvr2_hdw_commit_ctl(). Add pvr2_hdw_commit_ctl() calls to
the various ioctls that need this, and we can replace pvr2_v4l2_ioctl
by video_ioctl2.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>