mmc: uniphier-sd: migrate to CONFIG_DM_MMC_OPS

Catch up with the DM migration.

As struct dm_mmc_ops does not have .init callback, call the init
function directly from the probe function.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index 3616dee..a71afa5 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -80,6 +80,7 @@
 config MMC_UNIPHIER
 	bool "UniPhier SD/MMC Host Controller support"
 	depends on ARCH_UNIPHIER
+	select DM_MMC_OPS
 	help
 	  This selects support for the SD/MMC Host Controller on UniPhier SoCs.