power: qpnp-bms: report resistance property

Report the battery resistance through the power supply framework.

This is the estimated battery internal resistance, and will be used
by the battery current limiter driver to restrict current based on
voltage.

Change-Id: I7680ca4579171b154f324e7c714fb5c93acff2fc
Signed-off-by: Xiaozhe Shi <xiaozhes@codeaurora.org>