ARM: dts: msm: Fix vbus notification extcon producer on sdxpoorwills

sdxpoorwills-pcie-ep-cdp/mtp-256 device is incorrectly using smb1381
charger as vbus notification. Instead, sdxpoorwills-pcie-ep-cdp/mtp
device uses smb1381 charger and sdxpoorwills-pcie-ep-cdp/mtp-256 device
uses gpio based vbus detection.

Change-Id: I26cb86cffb484351d54261308be2dc598d202d86
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>