wifi: rtw88: Fill fw_version member of struct wiphy

wifi: rtw88: Fill fw_version member of struct wiphy

Let userspace tools like lshw show the firmware version by filling the
fw_version member of struct wiphy.

Before:

configuration: broadcast=yes driver=rtw88_8814au
driverversion=6.19.6-arch1-1 firmware=N/A link=no multicast=yes
wireless=IEEE 802.11

After:

configuration: broadcast=yes driver=rtw88_8814au
driverversion=6.19.6-arch1-1 firmware=33.6.0 link=no multicast=yes
wireless=IEEE 802.11

Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/3701cce1-42c4-4382-9120-cd21012c1b21@gmail.com