power: smb5-lib: Report charger detection status

Use the CHARGER_STATUS to report the charger-detection status
and INPUT_VOLTAGE_SETTLED to report input voltage, reading them
from SDAM.

While at it, clear the SMB_EN for CP in the shutdown path
to prevent SMB from being enabled in the next boot.

Change-Id: I269b0be18b56d56c0ab0e68ee1d7194d09824dd7
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>