USB: OTG: Reduce ACA ID polling timer period

The current ACA ID timer period is 2 sec. If charger is plugged
in or removed, the UI update will take 2 sec in the worst case.
Reduce the current period from 2 sec to 500 msec for better
UI experience.

CRs-Fixed: 346923
Change-Id: I933b22aa8d4dc517eb5a5bf3fa25ba7ce693411c
Signed-off-by: Chiranjeevi Velempati <cvelempa@codeaurora.org>