mx6cuboxi: enable OF_CONTROL and DM in SPL

In order to take the beneficts of DT and DM in SPL, like reusing the code
and avoid redundancy, enable SPL_OF_CONTROL, SPL_DM and SPL_DM_MMC.

With this new configuration SPL image is 50 KB, higher than the
38 KB from the previous version, but it still under the 68 KB limit.

Signed-off-by: Walter Lozano <walter.lozano@collabora.com>
diff --git a/configs/mx6cuboxi_defconfig b/configs/mx6cuboxi_defconfig
index 568cfce..bfb4b86 100644
--- a/configs/mx6cuboxi_defconfig
+++ b/configs/mx6cuboxi_defconfig
@@ -25,6 +25,7 @@
 CONFIG_PREBOOT="if hdmidet; then usb start; setenv stdin  serial,usbkbd; setenv stdout serial,vga; setenv stderr serial,vga; else setenv stdin  serial; setenv stdout serial; setenv stderr serial; fi;"
 CONFIG_BOUNCE_BUFFER=y
 CONFIG_BOARD_EARLY_INIT_F=y
+CONFIG_SPL_SEPARATE_BSS=y
 CONFIG_SPL_FS_EXT4=y
 CONFIG_SPL_I2C_SUPPORT=y
 CONFIG_SPL_WATCHDOG_SUPPORT=y
@@ -37,6 +38,7 @@
 CONFIG_CMD_EXT4_WRITE=y
 # CONFIG_SPL_PARTITION_UUIDS is not set
 CONFIG_OF_CONTROL=y
+CONFIG_SPL_OF_CONTROL=y
 CONFIG_DEFAULT_DEVICE_TREE="imx6dl-hummingboard2-emmc-som-v15"
 CONFIG_OF_LIST="imx6dl-hummingboard2-emmc-som-v15 imx6q-hummingboard2-emmc-som-v15"
 CONFIG_MULTI_DTB_FIT=y
@@ -45,6 +47,7 @@
 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG=y
 CONFIG_NET_RANDOM_ETHADDR=y
 CONFIG_DM=y
+CONFIG_SPL_DM=y
 CONFIG_DWC_AHSATA=y
 CONFIG_DM_MMC=y
 CONFIG_FSL_USDHC=y