memory: ti-emif: simplify platform_get_resource()

Use devm_platform_ioremap_resource() instead of platform_get_resource()
and devm_ioremap_resource().

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220419142859.380566-3-krzysztof.kozlowski@linaro.org