The memory we are accessing through virtual address has no IO side
effects. Moreover, for IO memory we have to use special accessors,
which we don't use.

Due to above, convert the driver to use memremap() instead of ioremap().
Tested-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20180308080020.22828-12-ard.biesheuvel@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>