wlan: Change number of descriptors for Low and High to 256.

The number of descriptors for high priority channel is 40 where as low
priority channel is 512.
We noticed that the voice traffic starve when we run multiple streams.

Change-Id: I69e280949f16f5aee4bf8b2874b70ccd2ac2ae24
CRs-Fixed: 383623
diff --git a/CORE/DXE/src/wlan_qct_dxe_cfg_i.c b/CORE/DXE/src/wlan_qct_dxe_cfg_i.c
index f132532..c08d0ba 100644
--- a/CORE/DXE/src/wlan_qct_dxe_cfg_i.c
+++ b/CORE/DXE/src/wlan_qct_dxe_cfg_i.c
@@ -176,7 +176,7 @@
    WLANDXE_CHANNEL_HANDLE_CIRCULA,
 
    /* Number of Descriptor, NOT CLEAR YET !!! */
-   512,
+   256,
 
    /* MAX num RX Buffer, NOT CLEAR YET !!! */
    1,
@@ -216,7 +216,7 @@
    WLANDXE_CHANNEL_HANDLE_CIRCULA,
 
    /* Number of Descriptor, NOT CLEAR YET !!! */
-   40,
+   256,
 
    /* MAX num RX Buffer, NOT CLEAR YET !!! */
    1,