qcacld-3.0: Avoid redefining WLAN_AKM_SUITE_FT_8021X

Linux kernel versions 4.12+ define WLAN_AKM_SUITE_FT_8021X. Avoid
redefining WLAN_AKM_SUITE_FT_8021X when compiling against 4.12+ Linux
kernels.

Change-Id: Iaaaeb0c348933c69034cb852191bed4d6a6862b1
CRs-Fixed: 2093922

core/hdd/src/wlan_hdd_cfg80211.c

@@ -192,7 +192,10 @@
 		.flags = flag, \
 	}
 
+#ifndef WLAN_AKM_SUITE_FT_8021X
 #define WLAN_AKM_SUITE_FT_8021X         0x000FAC03
+#endif
+
 #define WLAN_AKM_SUITE_FT_PSK           0x000FAC04
 
 #define HDD_CHANNEL_14 14