qcacld-3.0: Add support to get num_of_pwr level for 320 MHz chan width
Currently, support to get num_of_pwr level for 320 MHz chan width is
not present, so it is considered as Invalid channel width.
Add support to get num_of_pwr level for 320 MHz chan width
Change-Id: Iced6d58ac356bc85864ff4a240ca6f3ee35df94d
CRs-Fixed: 3478174