qcacmn: Make HTT PPDU TLV processing backward compatible

For HTT PPDU Stats TLVs, if target has provided less data than expected,
pad the data with zeros until it matches the expected length and
process the TLV, instead of     asserting.

This enables testing of different FW and Host versions during regression
analysis.

CRs-Fixed: 2451611
Change-Id: I79aaad8a6fde6d49510c3a212b21425ac784ad5c

dp/wifi3.0/dp_htt.h

@@ -60,6 +60,7 @@
 #define DP_SCAN_PEER_ID 0xFFFF
 
 #define DP_HTT_HTC_PKT_MISCLIST_SIZE          256
+#define HTT_T2H_MAX_MSG_SIZE 2048
 
 #define HTT_T2H_EXT_STATS_TLV_START_OFFSET    3