[ARM] 4554/1: replace consistent_sync() with flush_ioremap_region()

This fixes a regression from around 2.6.18, consistent_sync() will now BUG()
under these circumstances.  The use of consistent_sync() was a hack, replacing
it's usage here with a new function, flush_ioremap_region().

Signed-off-by: Jared Hulbert <jaredeh@gmail.com>
Acked-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>