USB: phy-msm-usb: Ensure strict order of phy event processing

Using system_nrt_wq does not guarantee the serial execution
of the multiple works. This can lead to parallel execution of
different tasks at the same time. It can lead to a situation
where state machine put device into low power mode and charger
detection still running and accessing registers. This will cause
unclocked access.

Use strict order workqueue to schedule state machine, charger
detection, ID detection, suspend work. workqueue is tunned to
run at max one task at any given point in time which helps avoid
parallel execution of different tasks.

CRs-Fixed: 765672
Change-Id: I02eb36dd4bcbea923638c6532fc4a94c3e5dd6b9
Signed-off-by: Sujeet Kumar <ksujeet@codeaurora.org>