DMA: PL330: Register the DMA controller with the generic DMA helpers

This patch registers the pl330 dma controller driver with the generic
device tree dma helper functions.

Signed-off-by: Padmavathi Venna <padma.v@samsung.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>