ARM: dts: msm: update wcnss device node for msm8909w BG v2

The wcn external gpio configuration has moved to WLAN firmware
code. To avoid the gpio resource request conflict and power offload
failure between wcnss platform driver and WLAN firmware.
Remove external gpio configuration from the wcnss device node.

Change-Id: Ib4f32a8553b4ef519bff412b6b84a147b7c2889e
Signed-off-by: Sarada Prasanna Garnayak <sgarna@codeaurora.org>