mhi: core: Abort system suspend to process pending events

mhi_trigger_resume() notifies the PM core of a wakeup event but
it does not request to abort the suspend. This causes event ring to
become full as mhi_runtime_resume() is not getting called to
process the events. Fix this issue by calling pm_wakeup_hard_event()
which kicks in pm resume.

CRs-Fixed: 2524066
Change-Id: I578d73cb48d8572edadf0e09e21906332c98d17a
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>