msm: kgsl: Increase GMU idle timeout to 100ms.

As per profiling there are cases when GMU timeout is taking more
than 10ms. Increase timeout to 100ms. This increase covers corner cases
and is not affecting general performance

Signed-off-by: Oleg Perelet <operelet@codeaurora.org>
Change-Id: I7d6c07a0b6e780d6b4d4cce84ea70b492583bde4
Signed-off-by: Urvashi Agrawal <urvaagra@codeaurora.org>