power_supply: Add clear_soh property

Add clear_soh property to the power supply framework so that it
can be used to indicate whether the battery is inserted for the
first time indicating a new battery. This can be used to clear
the SOH parameters.

Change-Id: I5ca88d973db7796cb6c9b1ca31d329cbef0589bd
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>