ARM: dts: msm: select external rsense for msm8226-dvt-v2 QRD

Since external rsense is used instead of internal one,
use-external-rsense should be enabled in the device tree.

Change-Id: I105c1bf66e67ab4f2a44c46c73aa49927e35185d
Signed-off-by: Xu Kai <kaixu@codeaurora.org>