media: vb2: set reqbufs/create_bufs capabilities

Upstream commit e5079cf1

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Set the capabilities field of v4l2_requestbuffers and v4l2_create_buffers.

The various mapping modes were easy, but for signaling the request capability
a new 'supports_requests' bitfield was added to videobuf2-core.h (and set in
vim2m and vivid). Drivers have to set this bitfield for any queue where
requests are supported.

Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Minor modifications required on the backport