scsi: eesox: use __iomem pointers for MMIO

ARM is moving to stricter checks on readl/write functions,
so we need to use the correct types everywhere.

Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>