qcacld-3.0: Do SSR cleanup during uevent/shutdown based on context

Currently we have two different cleanup approach for SSR. In case of
Adrastea hardware, cleanup can be done during the receipt of FW_DOWN
uevent while in case of HS/HSP it has to be defered to shutdown.

These two approaches are segregated by different branches and thus did
not need to coexist. But as part of future upgrades, a single component
would be used for both the hardware types.

To enable having both these paths, use the context of execution of the
pld_uevent as the differentiating agent. In case of interrupt context,
go with the deferred cleanup and in case of normal process context,
perform the cleanup in pld_uevent itself.

Change-Id: I554a10cdd99b17a6d3e059ebf7a157b0cddb6226
CRs-Fixed: 2669840