So far, the bsp for the mpc85xx target has been named "wdr4900" since
this device was the only one built from it.
Since all other files use the target name, though, use the target
name for mpc85xx as well.
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
Reviewed-by: Fabian Bläse <fabian@blaese.de>
