Simplify the way we handle TLB flushes. Since ARMv7 effectively has a

Simplify the way we handle TLB flushes.  Since ARMv7 effectively has a
unified TLB there is not much point in optimizing TLB flushing for pages
that have never been executable.  The only difference is a flush of the
branch predictor and even that isn't necessary anymore on all but the oldest
Cortex cores.

ok patrick@