[media] gsc-m2m: add device name sufix to bus_info capatiliby field

The driver doesn't set the device in the struct v4l2_capability bus_info
field so v4l2-compliance reports the following error for VIDIOC_QUERYCAP:

Required ioctls:
                fail: v4l2-compliance.cpp(537): missing bus_info prefix ('platform')
        test VIDIOC_QUERYCAP: FAIL

This patch fixes this by filling also the device besides the bus.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>