mt76x0: run vco calibration for each channel configuration

mt76x0: run vco calibration for each channel configuration

According to vendor sdk, vco calibration has to be executed
for each channel configuration whereas mcu calibration has to be
performed during channel scanning. This patch fixes the mt76x0
monitor mode issue since in that configuration vco calibration
was never executed

Fixes: 10de7a8b4ab9 ("mt76x0: phy files")
Tested-by: Sid Hayn <sidhayn@gmail.com>
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>