qpnp-fg-gen3: Use the correct property name to get fastcharge current

Currently GEN3 FG driver reads "qcom,nom-batt-capacity-mah"
property from the battery profile device node to use that for
notifying fastcharge current to the charger driver. Change that
to use "qcom,fastchg-current-ma" property which seems to be more
appropriate. Update all the battery profiles that are used with
GEN3 FG to follow that.

Change-Id: I119e6af297b37a06a227475f712f938367fb65bc
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>