mt76: mt76x0: use dev_debug instead of dev_err for hw_rf_ctrl

BIT(0) in MT_EE_NIC_CONF_1 is use to notify the driver if the radio RF
switch is controlled through a gpio. Use dev_debug instead of dev_err
to log this info.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>