qcacmn: Replace DEBUG macro with WLAN_DEBUG

This is a qcacld-2.0 to qcacld-3.0 propagation.

pr_debug() should not appear by default in kernel log (kmsg).
DEBUG is a kernel macro, since host driver is using the same name macro,
pr_debug log statements are appearing in kmsg.

Fix this by moving the code under DEBUG to WLAN_DEBUG and
remove DEBUG macro from Kbuild.

Change-Id: I5bb385f91f9b6ba15629a5878625fefc21d4a7e1
CRs-Fixed: 1003261

htc/htc.c

@@ -31,7 +31,7 @@
 #include <qdf_nbuf.h>           /* qdf_nbuf_t */
 #include <qdf_types.h>          /* qdf_print */
 
-#ifdef DEBUG
+#if defined(WLAN_DEBUG) || defined(DEBUG)
 static ATH_DEBUG_MASK_DESCRIPTION g_htc_debug_description[] = {
 	{ATH_DEBUG_SEND, "Send"},
 	{ATH_DEBUG_RECV, "Recv"},