FROMLIST: scsi: ufs: core: Fix the code for entering hibernation

Accessing a host controller register after the host controller has
entered the hibernation state may cause the host controller to exit the
hibernation state. Hence rework the hibernation entry code such that it
does not modify the interrupt enabled status. This patch relies on the
following:
* If an UIC command is submitted that should be completed by the UIC
  command completion interrupt, hba->uic_async_done == NULL.
* If an UIC command is submitted that should be completed by the power
  mode change interrupt or by a hibernation state change interrupt,
  hba->uic_async_done != NULL.

Change-Id: I1ae6ebbb6f0a17607258bb8f64539ba7e2c78314
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Bug: 344761008
Link: https://lore.kernel.org/linux-scsi/20240821182923.145631-2-bvanassche@acm.org/


Signed-off-by: Bart Van Assche <bvanassche@google.com>