mmc: Add Marvell Xenon SDHCI controller driver

This driver implementes platform specific code for the Xenon SDHCI
controller which is integrated in the Marvell MVEBU Armada 37xx and
Armada 7k / 8K SoCs.

History:
This driver is ported from the Marvell U-Boot version 2015.01 which is
written by Victor Gu <xigu@marvell.com> with minor changes ported from
the Linux driver which is written by Ziji Hu <huziji@marvell.com>.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
diff --git a/drivers/mmc/Makefile b/drivers/mmc/Makefile
index 4dca09c..6af7f79 100644
--- a/drivers/mmc/Makefile
+++ b/drivers/mmc/Makefile
@@ -68,6 +68,7 @@
 obj-$(CONFIG_MMC_SDHCI_S5P)		+= s5p_sdhci.o
 obj-$(CONFIG_MMC_SDHCI_SPEAR)		+= spear_sdhci.o
 obj-$(CONFIG_MMC_SDHCI_TEGRA)		+= tegra_mmc.o
+obj-$(CONFIG_MMC_SDHCI_XENON)		+= xenon_sdhci.o
 
 obj-$(CONFIG_MMC_SUNXI)			+= sunxi_mmc.o
 obj-$(CONFIG_MMC_UNIPHIER)		+= uniphier-sd.o