omap4: Use dma line defines from dma-44xx.h

This patch removes all the omap4 specific dma request
lines defines from plat/dma.h and includes dma-44xx.h

The defines are aligned so no driver should be impacted
because of this change.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Kevin Hilman <khilman@deeprootsystems.com>
Reviewed-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>