video: convert drivers/video/* to use module_platform_driver()

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

Cc: Ben Dooks <ben@simtec.co.uk>
Cc: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Wan ZongShun <mcuos.com@gmail.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Lennert Buytenhek <buytenh@wantstofly.org>
Acked-by: Alexey Charkov <alchark@gmail.com>
Acked-by: Damian Hobson-Garcia <dhobsong@igel.co.jp>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>