mmc: sdhci: make sdhci-of device drivers self registered

The patch turns the sdhci-of-core common stuff into helper functions
added into sdhci-pltfm.c, and makes sdhci-of device drviers self
registered using the same pair of .probe and .remove used by
sdhci-pltfm device drivers.

As a result, sdhci-of-core.c and sdhci-of.h can be eliminated with
those common things merged into sdhci-pltfm.c and sdhci-pltfm.h
respectively.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Anton Vorontsov <cbouatmailru@gmail.com>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index 732ec1e..cbd89c3 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -52,11 +52,10 @@
 sdhci-dove-objs				:= sdhci-pltfm.o
 obj-$(CONFIG_MMC_SDHCI_TEGRA)		+= sdhci-tegra.o
 sdhci-tegra-objs			:= sdhci-pltfm.o
-
-obj-$(CONFIG_MMC_SDHCI_OF)	+= sdhci-of.o
-sdhci-of-y				:= sdhci-of-core.o
-sdhci-of-$(CONFIG_MMC_SDHCI_OF_ESDHC)	+= sdhci-of-esdhc.o
-sdhci-of-$(CONFIG_MMC_SDHCI_OF_HLWD)	+= sdhci-of-hlwd.o
+obj-$(CONFIG_MMC_SDHCI_OF_ESDHC)	+= sdhci-of-esdhc.o
+sdhci-of-esdhc-objs			:= sdhci-pltfm.o
+obj-$(CONFIG_MMC_SDHCI_OF_HLWD)		+= sdhci-of-hlwd.o
+sdhci-of-hlwd-objs			:= sdhci-pltfm.o
 
 ifeq ($(CONFIG_CB710_DEBUG),y)
 	CFLAGS-cb710-mmc	+= -DDEBUG