ath11k: read country code from SMBIOS for WCN6855/QCA6390

This read the country code from SMBIOS and send the country code
to firmware, firmware will indicate the regulatory domain info of the
country code and then ath11k will use the info.

dmesg:
[ 1242.637173] ath11k_pci 0000:02:00.0: chip_id 0x2 chip_family 0xb board_id 0xff soc_id 0x400c0200
[ 1242.637176] ath11k_pci 0000:02:00.0: fw_version 0x110b09e5 fw_build_timestamp 2021-06-22 09:32 fw_build_id QC_IMAGE_VERSION_STRING=WLAN.HSP.1.1-02533-QCAHSPSWPL_V1_V2_SILICONZ_LITE-1
[ 1242.637253] ath11k_pci 0000:02:00.0: worldwide regdomain setting from SMBIOS
[ 1242.637259] ath11k_pci 0000:02:00.0: bdf variant name not found.
[ 1242.637261] ath11k_pci 0000:02:00.0: SMBIOS bdf variant name not set.
[ 1242.637263] ath11k_pci 0000:02:00.0: DT bdf variant name not set.
[ 1242.927543] ath11k_pci 0000:02:00.0: set current country pdev id 0 alpha2 00

Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3

Signed-off-by: Wen Gong <quic_wgong@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20220421023501.32167-1-quic_wgong@quicinc.com