ARM: shmobile: Remove unused mach/dma.h

Remove mach-shmobile mach/dma.h since it only
seems to be used on non-mach-shmobile platforms.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/mach-shmobile/include/mach/dma.h

-/* empty */