OMAP4: sDMA: Update the request lines and new registers.

This patch updates the platform dma.h with new dma request lines
for OMAP4 peripherals. Also additional hardware register of OMAP4
sDMA module are included.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>