scsi: ufs: core: Introduce a new clock_scaling lock

Introduce a new clock scaling lock to serialize access to some of the clock
scaling members instead of the host_lock. here also, simplify the code with
the guard() macro and co.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Avri Altman <avri.altman@wdc.com>
Link: https://lore.kernel.org/r/20241124070808.194860-5-avri.altman@wdc.com


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