wifi: rtw89: Fill fw_version member of struct wiphy

wifi: rtw89: 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=rtw89_8852au
driverversion=6.19.6-arch1-1 firmware=N/A link=no multicast=yes
wireless=IEEE 802.11

After:

configuration: broadcast=yes driver=rtw89_8852au
driverversion=6.19.6-arch1-1 firmware=0.13.36.2 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/a46ed12c-387c-4063-849c-c6457bf97810@gmail.com