power: fg-alg: add support for SOH profile loading

Add support for multiple profile loading based on SOH.
FG/QG driver can use soh_profile_init() for initialization and
call soh_profile_update() to update whenever there is a change
in SOH. Later, battery age level can be set based on SOH and
battery profile is loaded.

Change-Id: Id76c4ea0c90f9f8bd8096bc2b6ad7af767a013e1
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>