arm/dt: msm-pm8226: lower rconn to 0

The connector resistance is currently set to 18 milliohms. This is
incorrect. The hardware has been updated to do IR compensation on the
vbat_sns line, and the connector resistance is effectively zero.

Fix this in the device tree by setting the connector resistance to 0.

Change-Id: Iddd860cd675be708bcc6bbd3d8fc3dbb8e3c7c4f
Signed-off-by: Xiaozhe Shi <xiaozhes@codeaurora.org>