[media] convert drivers/media/* to use module_platform_driver()

This patch converts the drivers in drivers/media/* to use the
module_platform_driver() macro which makes the code smaller and a bit
simpler.

Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Hans Verkuil <hans.verkuil@cisco.com>
Cc: "Richard Röjfors" <richard.rojfors@pelagicore.com>
Cc: "Matti J. Aaltonen" <matti.j.aaltonen@nokia.com>
Cc: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: Manjunath Hadli <manjunath.hadli@ti.com>
Cc: Muralidharan Karicheri <m-karicheri2@ti.com>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Daniel Drake <dsd@laptop.org>
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Matti J. Aaltonen <matti.j.aaltonen@nokia.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>