qcacmn: Add Cached Descriptor support for DP SRNGs

Add support to configure any HAL SRNG descriptor to
be allocated from cached memory area. This is to
optimize of CPU cycles spent on uncached
memory accesses. Also added prefetch of cached
descriptors

Change-Id: I2544e8596d48e2f5549bf687a764c16d73397545
CRs-fixed: 2267945

wlan_cfg/wlan_cfg.h

@@ -24,6 +24,7 @@
  * or platform configuration
  */
 #if defined(CONFIG_MCL)
+#define WLAN_CFG_DST_RING_CACHED_DESC 0
 #define MAX_PDEV_CNT 1
 #define WLAN_CFG_INT_NUM_CONTEXTS 7
 #define WLAN_CFG_RXDMA1_ENABLE 1
@@ -38,6 +39,7 @@
 
 #define NUM_RXDMA_RINGS_PER_PDEV 2
 #else
+#define WLAN_CFG_DST_RING_CACHED_DESC 1
 #define MAX_PDEV_CNT 3
 #define WLAN_CFG_INT_NUM_CONTEXTS 11
 #define WLAN_CFG_RXDMA1_ENABLE 1