ARM: dts: msm: Add hard reset property for MSM8937

There is risk that system will not boot up when device is
rebooting with warm reset. So enable the DT property to set
the hard reset register's offset for MSM8937.

Change-Id: I06594702be790f4f607407b4ce54c5eb33e52ebc
Signed-off-by: Lijuan Gao <lijuang@codeaurora.org>