ARM: dts: msm: Remove the msm gpio node for msm8939

All msm8939 drivers need to use the pinctrl msm_gpio,
so retire the existing msm gpio controller node.

Change-Id: I33c45d54335621baddfce9a70a9b1584ab7f9947
Signed-off-by: Xiaocheng Li <lix@codeaurora.org>