scsi: ufs: core: Flush exception handling work when RPM level is zero

In the Linux kernel, the following vulnerability has been resolved:

scsi: ufs: core: Flush exception handling work when RPM level is zero

Ensure that the exception event handling work is explicitly flushed during

suspend when the runtime power management level is set to UFS_PM_LVL_0.

When the RPM level is zero, the device power mode and link state both

remain active. Previously, the UFS core driver bypassed flushing exception

event handling jobs in this configuration. This created a race condition

where the driver could attempt to access the host controller to handle an

exception after the system had already entered a deep power-down state,

resulting in a system crash.

Explicitly flush this work and disable auto BKOPs before the suspend

callback proceeds. This guarantees that pending exception tasks complete

and prevents illegal hardware access during the power-down sequence.