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/Kconfig b/drivers/mmc/host/Kconfig
index d9ca262..ee4ac77 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -81,18 +81,9 @@
 
 	  If unsure, say Y.
 
-config MMC_SDHCI_OF
-	tristate "SDHCI support on OpenFirmware platforms"
-	depends on MMC_SDHCI && OF
-	help
-	  This selects the OF support for Secure Digital Host Controller
-	  Interfaces.
-
-	  If unsure, say N.
-
 config MMC_SDHCI_OF_ESDHC
 	bool "SDHCI OF support for the Freescale eSDHC controller"
-	depends on MMC_SDHCI_OF
+	depends on MMC_SDHCI
 	depends on PPC_OF
 	select MMC_SDHCI_BIG_ENDIAN_32BIT_BYTE_SWAPPER
 	help
@@ -102,7 +93,7 @@
 
 config MMC_SDHCI_OF_HLWD
 	bool "SDHCI OF support for the Nintendo Wii SDHCI controllers"
-	depends on MMC_SDHCI_OF
+	depends on MMC_SDHCI
 	depends on PPC_OF
 	select MMC_SDHCI_BIG_ENDIAN_32BIT_BYTE_SWAPPER
 	help