e100, fix iomap read

There were 2 omitted readb's used on an iomap space. eliminate them
by using ioread8 instead.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
Cc: Bruce Allan <bruce.w.allan@intel.com>
Cc: PJ Waskiewicz <peter.p.waskiewicz.jr@intel.com>
Cc: John Ronciak <john.ronciak@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>