soc: qcom: Add in-rush current mitigation driver

On few recent targets APSS L2 memory is moved to APC domain which were
earlier on Mx domain. This can cause inrush current while bringing up
huge memories like modem and adsp.

To mitigate inrush current, bring up comparatively lesser memory in
size(for eg MDP memory) before bringing up huge memories like modem or
adsp. This way MDP memory introduce an intermediate load on MX rail.

During boot, gdsc driver will set MEM and PERIPHERAL bits. This driver
makes sure that dependent subsystems are powered up. Once done, call
gdsc_allow_clear_retention() API to allow retention of MDP memories.

Change-Id: I54011eb1b6cc38b2c33a67b8b9cc5eaadbd42c6a
Signed-off-by: Arun KS <arunks@codeaurora.org>