[media] media/platform: fix querycap

Querycap shouldn't set the version field (the core does that for you),
but it should set the device_caps field.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Scott Jiang <scott.jiang.linux@gmail.com>
Cc: Gerhard Sittig <gsi@denx.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>