mmc: Rename MMC_SUPPORT to MMC

Rename these options so that CONFIG_IS_ENABLED can be used with them.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
[trini: Fixup some incorrect renames]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/doc/README.SPL b/doc/README.SPL
index 0448835..c34c52e 100644
--- a/doc/README.SPL
+++ b/doc/README.SPL
@@ -49,7 +49,7 @@
 CONFIG_SPL_LIBDISK_SUPPORT (disk/libdisk.o)
 CONFIG_SPL_I2C (drivers/i2c/libi2c.o)
 CONFIG_SPL_GPIO (drivers/gpio/libgpio.o)
-CONFIG_SPL_MMC_SUPPORT (drivers/mmc/libmmc.o)
+CONFIG_SPL_MMC (drivers/mmc/libmmc.o)
 CONFIG_SPL_SERIAL_SUPPORT (drivers/serial/libserial.o)
 CONFIG_SPL_SPI_FLASH_SUPPORT (drivers/mtd/spi/libspi_flash.o)
 CONFIG_SPL_SPI_SUPPORT (drivers/spi/libspi.o)