OMAP: DMA: Convert DMA library into platform driver

Convert DMA library into DMA platform driver and make use of
platform data provided by hwmod data base for OMAP2+ onwards.

For OMAP1 processors, the DMA driver in mach-omap uses resource
structures for getting platform data.

Thanks to Tony Lindgren <tony@atomide.com> for fixing various
omap1 issues and testing the same on OSK5912 board.

Signed-off-by: G, Manjunath Kondaiah <manjugk@ti.com>
Tested-by: Kevin Hilman <khilman@deeprootsystems.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>