mmc: Add bcm2835 sdhost controller

The BCM2835 family of SoCs has 2 different SD controllers: One based on
the SDHCI spec and a custom, home-grown one.

This patch implements a driver for the latter based on the Linux driver.
This is needed so that we can make use of device trees that assume driver
presence of both SD controllers.

Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/MAINTAINERS b/MAINTAINERS
index aa161c8..af9965a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -97,6 +97,7 @@
 F:	arch/arm/mach-bcm283x/
 F:	drivers/gpio/bcm2835_gpio.c
 F:	drivers/mmc/bcm2835_sdhci.c
+F:	drivers/mmc/bcm2835_sdhost.c
 F:	drivers/serial/serial_bcm283x_mu.c
 F:	drivers/video/bcm2835.c
 F:	include/dm/platform_data/serial_bcm283x_mu.h