omap: complete removal of machine_desc.io_pg_offst and .phys_io

Commit ab69bcd6 (arm: remove
machine_desc.io_pg_offst and .phys_io) could not update
the new boards in the omap tree. This causes the build of
omap2plus_defconfig to fail. Fix this.

Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Eric Miao <eric.miao at canonical.com>
[tony@atomide.com: updated description]
Signed-off-by: Tony Lindgren <tony@atomide.com>