scsi: ufs: host: mediatek: Fix PWM mode switch issue

Address a failure in switching to PWM mode by ensuring proper
configuration of power modes and adaptation settings. The changes
include checks for SLOW_MODE and adjustments to the desired working mode
and adaptation configuration based on the device's power mode and
hardware version.

Signed-off-by: Peter Wang <peter.wang@mediatek.com>
Link: https://lore.kernel.org/r/20250811131423.3444014-6-peter.wang@mediatek.com


Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>