mt76: mt76x0: handle chip specific initval differences

mt76: mt76x0: handle chip specific initval differences

Some RF registers need different values for various chips.
For at least mt76x0_rf_central_tab registers, overwriting them later does
not work, as the wrong values can cause the entire system to hang on some
devices with MT7610E

Signed-off-by: Felix Fietkau <nbd@nbd.name>