Revert "ARM: dts: msm: Add support for secure kgsl iommu"

This reverts commit b44e72d2

The graphics driver attaches the secure context bank in
a non secure domain, which causes crash. Reverting support
for secure kgsl iommu till graphics support for same is
available.

Change-Id: Icf7a3a7d0a004775d4c03ba76f164039917c68bc
Signed-off-by: Pothuluraiah Usarthi <usarthip@codeaurora.org>
Signed-off-by: Sridhar Parasuram <sridhar@codeaurora.org>