ARM: SAMSUNG: remove unused DMA infrastructure

Everything uses dmaengine now, so there is no reason to
keep this around any longer. Thanks to everyone who was involved
in moving the users over to use the dmaengine APIs.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Kukjin Kim <kgene@kernel.org>