power: smb5-lib: Fix charger reverse boost on soft JEITA

Currently, USB input will be suspended on soft JEITA condition when
Vbatt goes above JEITA float voltage to avoid reverse boost as per the
hardware recommendation, but this is causing charging fluctuations
whenever the battery goes in and out of soft JEITA condition.

As per the hardware recommendation, disable charging instead of
suspending input, and utilize the charge inhibit feature to fix possible
reverse boost.

Since this configuration requires to know the FCC/FV values that needs
to be applied for soft JEITA conditions, add support to read it from
battery profile device tree through the following properties:
qcom,jeita-soft-fcc-ua, qcom,jeita-soft-fv-uv.

This change has also been updated to address cyclomatic complexity
issues in smb5_batt_get_prop().

Change-Id: I1a54d30eb878aab34abd5d4e22d8f09ed24e115d
Signed-off-by: Harry Yang <harryy@codeaurora.org>
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>
Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>