mmc: Add realtek pcie sdmmc host driver

Realtek PCI-E SD/MMC card host driver is used to access SD/MMC card,
with the help of Realtek PCI-E card reader MFD driver.
Signed-off-by: Wei WANG <wei_wang@realsil.com.cn>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mmc/host/Kconfig

@@ -621,3 +621,10 @@ config MMC_USHC
 
 	  Note: These controllers only support SDIO cards and do not
 	  support MMC or SD memory cards.
+
+config MMC_REALTEK_PCI
+	tristate "Realtek PCI-E SD/MMC Card Interface Driver"
+	depends on MFD_RTSX_PCI
+	help
+	  Say Y here to include driver code to support SD/MMC card interface
+	  of Realtek PCI-E card reader

drivers/mmc/host/Makefile

@@ -46,6 +46,8 @@ obj-$(CONFIG_MMC_JZ4740)	+= jz4740_mmc.o
 obj-$(CONFIG_MMC_VUB300)	+= vub300.o
 obj-$(CONFIG_MMC_USHC)		+= ushc.o
 
+obj-$(CONFIG_MMC_REALTEK_PCI)	+= rtsx_pci_sdmmc.o
+
 obj-$(CONFIG_MMC_SDHCI_PLTFM)		+= sdhci-pltfm.o
 obj-$(CONFIG_MMC_SDHCI_CNS3XXX)		+= sdhci-cns3xxx.o
 obj-$(CONFIG_MMC_SDHCI_ESDHC_IMX)	+= sdhci-esdhc-imx.o