media: coda: limit frame interval enumeration to supported encoder frame sizes

Let VIDIOC_ENUM_FRAMEINTERVALS return -EINVAL if userspace queries
frame intervals for frame sizes unsupported by the encoder. Fixes the
following v4l2-compliance failure:

		fail: v4l2-test-formats.cpp(123): found frame intervals for invalid size 47x16
		fail: v4l2-test-formats.cpp(282): node->codec_mask & STATEFUL_ENCODER
	test VIDIOC_ENUM_FMT/FRAMESIZES/FRAMEINTERVALS: FAIL

[hverkuil: drop incorrect 'For decoder devices, return -ENOTTY.' in the commit log]

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>