power: qpnp-charger: disable ULPM when charging

When charging ULPM needs to be disabled.

Implement this by disabling ULPM upon charger
insertion and re-enabling it upon charger removal.

Also add logic to handle the aggregatin of the
regulator framework requests in combination
with the charging ULPM requirements.

Change-Id: Iae28679d367c0a737ef43f75bcc59289be580471
CRs-Fixed: 539624
Signed-off-by: David Keitel <dkeitel@codeaurora.org>