ath11k: add configure country code for QCA6390 and WCN6855

Add handler to send WMI_SET_CURRENT_COUNTRY_CMDID to firmware which
is used for QCA6390 and WCN6855.

Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-01720.1-QCAHSPSWPL_V1_V2_SILICONZ_LITE-1
Tested-on: QCA6390 hw2.0 PCI WLAN.HST.1.0.1-01740-QCAHSTSWPLZ_V2_TO_X86-1

Signed-off-by: Wen Gong <quic_wgong@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20211201071745.17746-3-quic_wgong@quicinc.com