msm: kgsl: Fix global pagetable use case

When using global pagetables allow the secure pagetable
to be created as a seperate table. Secure table should
always be different since it has special attributes. This
allows the system to boot up when global pagetable is used.

Change-Id: I1dee50019744594bac1875282c9727891647253b
Signed-off-by: Shubhraprakash Das <sadas@codeaurora.org>