realtek: phy: drop external RTL8218B firmware blob
No one has looked into the firmware based RTL8218B initializations
for a long time. Instead the basic setup sequences have evolved
so that they can start the RTL8218B PHY from scratch. See
19bc6e8 ("realtek: phy: add basic RTL8218B setup")
4fa90d8 ("realtek: phy: enhance RTL8218B initialization")
Drop the legacy coding.
Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
Link: https://github.com/openwrt/openwrt/pull/21679
Signed-off-by: Robert Marko <robimarko@gmail.com>