regulator: qpnp-amoled: Skip changing IBB/AB configurations for AOD

As per the hardware recommendation, allow only PD control
configuration changes during regulator mode transition and
remove other register writes for AB/IBB peripherals during
AOD entry/exit or standby modes.

Since "qcom,aod-entry-poll-time-ms" is not needed anymore,
remove it.

CRs-Fixed: 2517986
Change-Id: I4816f3636757f53b9d6c0c13aa68f1fb1dbb9669
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>