ARM: mvebu: remove Armada 375 Z1 workaround for I/O coherency

This reverts commit 5ab5afd8 ("ARM: mvebu: implement Armada 375
coherency workaround"), since we are removing the support for the very
early Z1 revision of the Armada 375 SoC.

This commit is an exact revert, with two exceptions:

 - minor adaptations needed due to other changes that have taken place
   in coherency.c since the original commit

 - keep the definition of pr_fmt. This shouldn't originally have been
   part of the Armada 375 Z1 workaround commit since it had nothing to
   do with it.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1415871540-20302-5-git-send-email-thomas.petazzoni@free-electrons.com


Signed-off-by: Jason Cooper <jason@lakedaemon.net>