input: powerkey: don't send dummy release event

It will send dummy release event when pressing power key to wake up
system. This behavior makes long press event detection failed when
system suspends.
Add INPUT_PROP_NO_DUMMY_RELEASE for power key to avoid this behavior.

Change-Id: If6657af944a62cde2e67da6a9ac5cfc0e7cac458
Signed-off-by: Kun Liang <kunliang@codeaurora.org>