power: qpnp-smbcharger: Read the hi-power property

Read the hi-power power-supply property in the
get_property callback to avoid warnings from the
power-supply framework.

Change-Id: I5a9bb9b625ceb308afab915db9ac784a567ffbfb
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>