V4L/DVB (11265): stkwebcam: Remove buffer type check from g_parm and q/dq/reqbufs

The v4l2-ioctl core only allows buffer types for which the corresponding
->vidioc_try_fmt_xxx() methods are defined to be used with
vidioc_(q|dq|query)bufs(), vidioc_reqbufs() and now vidioc_(s|g)_parm.

This driver only defines ->vidioc_try_fmt_vid_cap() so only VIDEO_CAPTURE
buffers are allowed to be used with vidioc_g_parm(), vidioc_qbuf(),
vidioc_dqbuf(), and vidioc_reqbufs().

Cc: Jaime Velasco Juan <jsagarribay@gmail.com>
Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>