mx23_olinuxino: convert MMC to driver model

Convert the Olimex Olinuxino board's support for MMC to driver model following
Fabio Estevam's excellent example from:

	commit: 23013aa9619881290dbeb6217f1fab863869050e:
	mx23evk: Convert to driver model

Signed-off-by: Trevor Woerner <twoerner@gmail.com>
diff --git a/configs/mx23_olinuxino_defconfig b/configs/mx23_olinuxino_defconfig
index 2bf6818..680611c 100644
--- a/configs/mx23_olinuxino_defconfig
+++ b/configs/mx23_olinuxino_defconfig
@@ -12,6 +12,7 @@
 CONFIG_SPL_SERIAL_SUPPORT=y
 CONFIG_SPL=y
 CONFIG_DEFAULT_DEVICE_TREE="imx23-olinuxino"
+# CONFIG_SYS_MALLOC_F is not set
 CONFIG_BOOTDELAY=3
 # CONFIG_DISPLAY_BOARDINFO is not set
 CONFIG_ARCH_MISC_INIT=y
@@ -30,6 +31,7 @@
 CONFIG_ENV_IS_IN_MMC=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_VERSION_VARIABLE=y
+CONFIG_DM=y
 CONFIG_MXS_GPIO=y
 CONFIG_LED_STATUS=y
 CONFIG_LED_STATUS_GPIO=y
@@ -39,10 +41,10 @@
 CONFIG_LED_STATUS_BOOT_ENABLE=y
 CONFIG_LED_STATUS_BOOT=0
 CONFIG_LED_STATUS_CMD=y
+CONFIG_DM_MMC=y
 CONFIG_MMC_MXS=y
 CONFIG_CONS_INDEX=0
 CONFIG_USB=y
 CONFIG_USB_EHCI_HCD=y
-CONFIG_USB_STORAGE=y
 CONFIG_USB_HOST_ETHER=y
 CONFIG_USB_ETHER_SMSC95XX=y