V4L/DVB: OMAP_VOUT:Build FIX: Rebased against latest DSS2 changes

Changes -
	- Kconfig option dependancy changed to ARCH_OMAP2/3 from
	ARCH_OMAP24XX/34XX
	- There are some moments of function from omap_dss_device
	to omap_dss_driver. Incorporated changes for the same.

Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>
Signed-off-by: Muralidharan Karicheri <mkaricheri@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>