memstick: Add realtek USB memstick host driver

Realtek USB memstick host driver provides memstick host support based on the
Realtek USB card reader MFD driver.
Signed-off-by: Roger Tseng <rogerable@realtek.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/memstick/host/Kconfig

@@ -52,3 +52,13 @@ config MEMSTICK_REALTEK_PCI
 
 	  To compile this driver as a module, choose M here: the module will
 	  be called rtsx_pci_ms.
+
+config MEMSTICK_REALTEK_USB
+	tristate "Realtek USB Memstick Card Interface Driver"
+	depends on MFD_RTSX_USB
+	help
+	  Say Y here to include driver code to support Memstick card interface
+	  of Realtek RTS5129/39 series USB card reader
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called rts5139_ms.

drivers/memstick/host/Makefile

@@ -6,3 +6,4 @@ obj-$(CONFIG_MEMSTICK_TIFM_MS)		+= tifm_ms.o
 obj-$(CONFIG_MEMSTICK_JMICRON_38X)	+= jmb38x_ms.o
 obj-$(CONFIG_MEMSTICK_R592)		+= r592.o
 obj-$(CONFIG_MEMSTICK_REALTEK_PCI)	+= rtsx_pci_ms.o
+obj-$(CONFIG_MEMSTICK_REALTEK_USB)	+= rtsx_usb_ms.o