platform: qpnp-power-on: decrease polling time for QPNP keys

Decrease polling time to make sure that the key release status
is detected quicker.  The present delay resulted in a long
press, causing the userspace to misbehave.

Change-Id: Ib038f85f5d74486138342234f0cb040453c3dd74
Signed-off-by: Amy Maloche <amaloche@codeaurora.org>