ARM: dts: msm: Update reset configuration for PMx8950

Add following configurations for PON module
PMI8950:
- remove S3 reset configuration.
- add 'qcom,cfg-shutdown-for-hard-reset' DT property to
  configure PS_HOLD reset type to SHUTDOWN.
PM8950:
- remove all reset configuration.

Change-Id: I93df179a241c46664426c1e8dea035e38fad0fa2
Signed-off-by: Ashay Jaiswal <ashayj@codeaurora.org>