esoc: Move polling of the gpio from an interrupt context

A previous change (<8a1a8624> esoc: Check for modem status LOW
prior to error handling) introduced a bug wherein the driver polls
the gpio line for 3 seconds in an interrupt context, leading
to a watchdog bark. Hence, move the polling logic to a scheduled
work item in the same path.

Change-Id: I8ff17d354175920610f9ce69ed47e362f2de055d
Signed-off-by: Raghavendra Rao Ananta <rananta@codeaurora.org>