ramips: mt76x8: fix build due to renamed U-Boot binary
The U-Boot binary for the RAVPower RP-WD009 has been renamed.
In order to be uniform with all other U-Boot binaries generated the SoC type has been prepended.
Set that new name also in the image build recipe for that device in order to fix build.
Fixes: 927334a8f7 ("uboot-mediatek: add basic build for ZBT-WG3526 (MT7621, 16M SPI-NOR)")
Signed-off-by: Daniel Golle <[email protected]>
Daniel Golle