ARM: dts: msm: Add hard reset property for PM8994 PON peripheral

Define the qcom,store-hard-reason-reason property in the PM8994 PON
device so that a reset reason can be stored into a spare register
of the PON peripheral. This enables hard resets in scenarios
where warm resets would otherwise be necessary.

Change-Id: Ibe4307dd9ba835d14848f317ea1a523440e70936
Signed-off-by: Osvaldo Banuelos <osvaldob@codeaurora.org>