mmc: dw_mmc-pltfm: don't check resource with devm_ioremap_resource

devm_ioremap_resource does sanity checks on the given resource.
No need to duplicate this in the driver.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Seungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>