mmc: meson: add MMC driver for Meson GX (S905)

This driver implements MMC support on Meson GX (S905) based systems.
It's based on Carlo Caione's work, changes:
- BLK support added
- general refactoring

Signed-off-by: Carlo Caione <carlo@caione.org>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Tested-by: Vagrant Cascadian <vagrant@debian.org>
diff --git a/drivers/mmc/Makefile b/drivers/mmc/Makefile
index 6a26a52..a61a9e9 100644
--- a/drivers/mmc/Makefile
+++ b/drivers/mmc/Makefile
@@ -29,6 +29,7 @@
 obj-$(CONFIG_GENERIC_MMC) += mmc_boot.o
 endif
 obj-$(CONFIG_GENERIC_ATMEL_MCI) += gen_atmel_mci.o
+obj-$(CONFIG_MMC_MESON_GX) += meson_gx_mmc.o
 obj-$(CONFIG_MMC_SPI) += mmc_spi.o
 obj-$(CONFIG_MVEBU_MMC) += mvebu_mmc.o
 obj-$(CONFIG_MMC_OMAP_HS)		+= omap_hsmmc.o