wifi: rtw88: Set efuse->ext_lna_5g - fix typo

efuse->ext_lna_2g is set twice and efuse->ext_lna_5g is not set at all.
Set each one once.

Nothing uses these members right now. They will be used by the RTL8821AU
and RTL8812AU drivers.

Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>
Acked-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/8ccc9e13-0d45-417d-8f88-93a0ad294f77@gmail.com