realtek: phy: add comment to firmware file definition
Add a comment stating the situation around a specific RTL838x firmware
file. After SerDes setup has been moved to the PCS driver, this firmware
file is partially unused. If the remaining bits are pulled out or just
replaced, this firmware file can be dropped. The comment ensures that we
do not forget about that.
Signed-off-by: Jonas Jelonek <jelonek.jonas@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/21481
Signed-off-by: Robert Marko <robimarko@gmail.com>