Revert " ARM: 7559/1: smp: switch away from the idmap before updating init_mm.mm_count"

Change-Id: Ia8875ee86a3b89c78f1213135ebc4749c71bf885
Merge "Revert " ARM: 7559/1: smp: switch away from the idmap before updating init_mm.mm_count"" into kk4.4