dm: spl: Allow driver model to be used

When enabled, set up driver model for SPL. This allows SPL to use the same
drivers as the main U-Boot.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Tom Rini <trini@ti.com>
diff --git a/scripts/Makefile.spl b/scripts/Makefile.spl
index 07db0bf..6e13f68 100644
--- a/scripts/Makefile.spl
+++ b/scripts/Makefile.spl
@@ -69,6 +69,7 @@
 libs-$(CONFIG_SPL_FRAMEWORK) += common/spl/
 libs-$(CONFIG_SPL_LIBCOMMON_SUPPORT) += common/
 libs-$(CONFIG_SPL_LIBDISK_SUPPORT) += disk/
+libs-$(CONFIG_SPL_DM) += drivers/core/
 libs-$(CONFIG_SPL_I2C_SUPPORT) += drivers/i2c/
 libs-$(CONFIG_SPL_GPIO_SUPPORT) += drivers/gpio/
 libs-$(CONFIG_SPL_MMC_SUPPORT) += drivers/mmc/