power: qpnp-fg-gen4: Get charge pump enable status for ESR FCC config

Currently, FG driver reads SMB_EN_MODE property to determine
whether charge pump is enabled or not for changing ESR FCC
configuration. This doesn't work well when the charge pump is
disabled. Instead of this, read cp_disable votable that indicates
the charge pump switcher status properly and make use of it for
changing ESR FCC configuration.

Change-Id: Id70f97c7df63d07741f314b65e567b9df0901e73
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>