ARM: dts: msm: Remove unnecessary clocks for kgsl_iommu for sdm845

Additional clocks were listed in devicetree which are not required. Remove
them to reduce power use.

Change-Id: Ia357dadf0bff5dc91c9e55e83e9e78124291b644
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>