DMA: Move dma_pool_destroy to free channel

DMA: Move dma_pool_destroy to free channel

BZ: 31979

The DMA pool for LLI is destroyed in atomic context.
This function might sleep and it should not be called in atomic
context.

Moved the destroying of the DMA pool to free channel resource
function.

Change-Id: I7624a69de3d8a3815fb0b3733cf441a246aea045
Signed-off-by: Shreyas Neerebailoor <shreyasx.neerebailoor@intel.com>
Reviewed-on: http://android.intel.com:8080/44152
Reviewed-by: Abdullah, Omair M <omair.m.abdullah@intel.com>
Reviewed-by: Bensaid, Selma <selma.bensaid@intel.com>
Reviewed-by: Babu, Ramesh <ramesh.babu@intel.com>
Reviewed-by: Koul, Vinod <vinod.koul@intel.com>
Reviewed-by: Gupta, ArvindX K <arvindx.k.gupta@intel.com>
Reviewed-by: M, Arulselvan <arulselvan.m@intel.com>
Tested-by: M, Arulselvan <arulselvan.m@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>