drm/msm: Fix duplicate gpu node in icc summary

The dev_pm_opp_of_add_table() api initializes the icc nodes for gpu
indirectly. So we can avoid using of_icc_get() api in the common
probe path. To improve this, move of_icc_get() to target specific code
where it is required.

This patch helps to fix duplicate gpu node listed in the interconnect
summary from the debugfs.

Signed-off-by: Akhil P Oommen <akhilpo@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>