wlan: Fix the incorrect channel type update to hostapd in 2.4G

The channel bonding parameter used in 2.4G for AP mode is
channelBondingAPMode24GHz but during updation to hostapd
channelBondingMode24GHz is used for calculation of channel_type.
This leads to incorrect updation of channel type to hostapd in 2.4GHz.

Fix this by use of correct channel bonding parameter 
channelBondingAPMode24GHz for notification to hostapd.

Change-Id: Iee1d90504eee8704cf7cc511c1cc394e98b54309
CRs-Fixed: 2777056