scsi: ufs: Add simple IRQ-affined PM QoS operations

Qualcomm's PM QoS solution suffers from a number of issues: applying
PM QoS to all CPUs, convoluted spaghetti code that wastes CPU cycles,
and keeping PM QoS applied for 10 ms after all requests finish
processing.

This implements a simple IRQ-affined PM QoS mechanism for each UFS
adapter which uses atomics to elide locking, and enqueues a worker to
apply PM QoS to the target CPU as soon as a command request is issued.

Change-Id: I634873deb7baf0916208809c025eb0d3ccdb0fa3
Signed-off-by: Sultan Alsawaf <sultan@kerneltoast.com>
Signed-off-by: Alexander Winkowski <dereference23@outlook.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>