msm: kgsl: remove unneeded idle calls from context create

These idles were necessary when the context switch code
preserved PM_OVERRIDE registers. That was removed some time
ago so now the idles are not needed.

CRs-Fixed: 331325
Change-Id: I90d4e1685f213a5720bf6da4e6d4a187d1eb0689
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>