ARM: mach-shmobile: sh73a0 DMA Engine support for SY-DMAC

Add SY-DMAC support via shdma.c to the sh73a0 SoC
including slave ids, platform data and clock bindings.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>