wifi: ath11k: use proper regulatory reference for bands

wifi: ath11k: use proper regulatory reference for bands

Currently, during regulatory event, 2 GHz/5 GHz is referred
to as 2G/5G including variable names. However, there is no
such entity as 2G or 5G.

Re-name such occurences to its proper name. No functional changes.

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.7.0.1-01744-QCAHKSWPL_SILICONZ-1
Tested-on: QCN9074 hw1.0 PCI WLAN.HK.2.7.0.1-01744-QCAHKSWPL_SILICONZ-1
Tested-on: QCN9074 hw1.0 PCI WLAN.HK.2.5.0.1-01100-QCAHKSWPL_SILICONZ-1

Signed-off-by: Aditya Kumar Singh <quic_adisi@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230110121024.14051-2-quic_adisi@quicinc.com