qcacmn: populate NSS value and Translate MCS value for HT

This change will resolve displaying NSS value
in stats in case of HT. And also it will give
proper NSS value to calculate rate value. Modify MCS
value to match with Tx stats from firmware.

Also retain original MCS value to use in radiotap code
for HT case.

Change-Id: I4dad068262a5e9188a5935db6b2cbf8d14138e7e

hal/wifi3.0/hal_api_mon.h

@@ -130,6 +130,7 @@
 #define HE_LTF_4_X 3
 #define HE_LTF_UNKNOWN 0
 #define VHT_SIG_SU_NSS_MASK	0x7
+#define HT_SIG_SU_NSS_SHIFT	0x3
 
 #define HAL_TID_INVALID 31
 #define HAL_AST_IDX_INVALID 0xFFFF