Revert "ARM: dts: msm: enable dsi phy idle mode for sdm845"

This reverts commit 60d737a6.
With CX power collapse together with dsi phy idle mode feature,
we are seeing DSI PLL locking issues. Disable the feature
temporarily.

Change-Id: I7da0a3612089ff38ced99e93ba69b258cdafa4fa
Signed-off-by: Vara Reddy <varar@codeaurora.org>