dmaengine: pl330: Remove duplicated cachecontrol enum

The settings for destination and source cache control are exactly the same. This
patch removes the duplicated enum and uses the same for both destination and
source cache control.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>