power: qpnp-fg-gen4: Fix disabling mem_attn interrupt

Currently, mem_attn interrupt is enabled whenever parallel
current summing configuration needs to be changed which is based
on the input presence or charge termination. It is disabled once
the configuration is complete. However, when there is frequent
changes in charging status or input presence, parallel current
summing configuration stays unaffected leaving mem_attn interrupt
enabled for longer duration. Fix it.

Change-Id: I143b2ca73d1d39c4469f06786666478715d7b71d
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>