Revert "msm: kgsl: Protect SMMU registers from being written by the GPU"

This reverts commit a840f443539a707e417772384cc71cd3189252ca.
Revert "msm: kgsl: Mark the IOMMU setstate memory as read only"

This reverts commit b1a702c933e58927ab08101b2e4cb0d9625e0a0d.
Revert "msm: kgsl: Protect CP_STATE_DEBUG_INDEX"

This reverts commit 412e3721e71f4ed561f5ce5b018949f4cfaa954a.
Revert "msm: kgsl: Enable protected mode for A3XX"

This reverts commit 80d14fbd7ab143ec5d9cb3646cd1684001682127.