mmc: renesas-sdhi: Add Renesas SDHI Kconfig entry

Add Kconfig entry for the Renesas SDHI variant of the controller
and split the Makefile entries accordingly.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/drivers/mmc/Makefile b/drivers/mmc/Makefile
index 25eb669..f2c6280 100644
--- a/drivers/mmc/Makefile
+++ b/drivers/mmc/Makefile
@@ -62,5 +62,6 @@
 obj-$(CONFIG_MMC_SDHCI_ZYNQ)		+= zynq_sdhci.o
 
 obj-$(CONFIG_MMC_SUNXI)			+= sunxi_mmc.o
-obj-$(CONFIG_MMC_UNIPHIER)		+= matsushita-common.o uniphier-sd.o renesas-sdhi.o
+obj-$(CONFIG_MMC_UNIPHIER)		+= matsushita-common.o uniphier-sd.o
+obj-$(CONFIG_RENESAS_SDHI)		+= matsushita-common.o renesas-sdhi.o
 obj-$(CONFIG_MMC_BCM2835)		+= bcm2835_sdhost.o