staging: apf: Enable MPSoC SG-DMA and removed clock control

staging: apf: Enable MPSoC SG-DMA and removed clock control

This patch enables preliminary scatter-gather support for the
apf DMA driver.  This extends only to memory allocated by a call
to sds_alloc, and dma_buf shared buffers.  Zynq support is
unchanged.  Additionally, control over clocks has been removed
due to clocks being correctly configured during petalinux
boot. There is no impact of this on a user.

Signed-off-by: Michael Gill <gill@xilinx.com>
Tested-by : Radhey Shyam Pandey <radheys@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>