Some compilation fallout from UM Linux (which does not have
IOMEM) makes it necessary to depend on HAS_IOMEM for drivers
that doesn't have other factors restricting their selection.

Cc: Phil Reid <preid@electromag.com.au>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Reported-by: R. Daneel Olivaw <kbuild-all@01.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>