ARM: dts: apq8084: Remove bark interrupt for power button

Current power buton codes are imported from 8974. As early 8974 has
problem with change state interrupt, bark interrupt was introduced.
APQ8084 does not have issues with change state interrupt. Bark
interrupt is not needed.

Change-Id: I838a979f11e7908a065ba703137feda33c578098
Signed-off-by: Chun Zhang <chunz@codeaurora.org>