mvebu: clearfog: require uboot-mvebu-clearfog
The u-boot variant for the clearfog is provided by the uboot-mvebu-clearfog,
and not by the generic uboot-mvebu packae.
Make sure the clearfog variant is selected when building for it.
Signed-off-by: Josua Mayer <[email protected]>
Signed-off-by: Felix Fietkau <[email protected]>