qcacld-3.0: Remove HDD_CHANNEL_14 macro

Change I8ba344ce5593df44bd15527e2ff68e872b6d23b8 ("qcacld-3.0: TDLS:
remove legacy core functions") removed the only reference to macro
HDD_CHANNEL_14. Since it is now obsolete, remove it.

Change-Id: I41267b0e5aef8f60c8a48cd9154529b2689bab5f
CRs-Fixed: 2368716

core/hdd/src/wlan_hdd_cfg80211.c

@@ -180,8 +180,6 @@
 #define WLAN_AKM_SUITE_FT_PSK           0x000FAC04
 #endif
 
-#define HDD_CHANNEL_14 14
-
 #define IS_DFS_MODE_VALID(mode) ((mode >= DFS_MODE_NONE && \
 			mode <= DFS_MODE_DEPRIORITIZE))
 /*