wlan: check for max channels

Add a condition to check max channel limit before issuing scan
request.

Change-Id: I39cd50caf8acd25fc64c39357ca2c5f6c5dac2be
CRs-fixed: 649618.
diff --git a/CORE/HDD/inc/wlan_hdd_cfg80211.h b/CORE/HDD/inc/wlan_hdd_cfg80211.h
index e552883..929c48a 100644
--- a/CORE/HDD/inc/wlan_hdd_cfg80211.h
+++ b/CORE/HDD/inc/wlan_hdd_cfg80211.h
@@ -101,6 +101,8 @@
 #endif
 #endif
 
+#define MAX_CHANNEL MAX_2_4GHZ_CHANNEL + NUM_5GHZ_CHANNELS
+
 typedef struct {
    u8 element_id;
    u8 len;