configs/rock5b: add firmware for the RTL8125 NIC
Add the proper firmware to avoid the following warning + error during
boot:
r8169 0004:41:00.0: Direct firmware load for rtl_nic/rtl8125b-2.fw failed with error -2
r8169 0004:41:00.0: Unable to load firmware rtl_nic/rtl8125b-2.fw (-2)
Note that the NIC appears functional even without the proper firmware.
However, add the firmware anyway, since the error messages are distracting
and clutters dmesg.
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>