Revert "ARM: smp: Wait just 1 second for other CPU to halt"

This reverts commit 59f1ca90bced71ef9e9a4d3dbe47f5d61fd9f466.
Revert "CHROMIUM: mm: Fix calculation of dirtyable memory"

This reverts commit 3357ae1604e84ca70e0ae4561c8f57feb39408b2.