ARM: dts: msm: remove gpio dt entry for configuring mictor on 8974

The CoreSight TPIU driver uses pin control framework to configure
mictor for TPIU trace and falls back on gpio lib if pin control
framework is unavailable. Remove device tree entry for gpio lib
configurations on MSM8974 since pin control support is available
for this chipset.

Change-Id: I3d2501e7d6eb50b1d254c0f550a67cf3ce64db45
Signed-off-by: Aparna Das <adas@codeaurora.org>