mt76x0: pci: fix ACS support

Fix Automatic Channel Selection (ACS) support in mt76x0e driver
configuring properly MT_CH_TIME_CFG register

Fixes: 62503186 ("mt76x0: pci: add get_survey support")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>