Wifi: Add frequency list to chanelPrams in hostapd

This commit adds a new parameter to the channel parameters for IHostapd
Hidl interface to handle a list of channel freq in MHz to be used in
ACS. This is needed as part of support of Wifi 6GHz band since 6GHz band
channels use same channel numbers as 2.4/5GHz bands.

Bug: 146186687
Bug: 139354972
Test: Manual
Test: VTS test
Change-Id: I8692f3cd28cfaae1d3b870c9f8dbcdd2ff350ee4