mx6memcal: fix build

Commit 45032991 has a side effect on this board, and build is broken.
Adjust mx6memcal_defconfig to build it again.
Signed-off-by: NStefano Babic <sbabic@denx.de>

configs/mx6memcal_defconfig

@@ -39,6 +39,7 @@ CONFIG_SYS_MEMTEST_END=0x20000000
 CONFIG_CMD_CACHE=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 # CONFIG_NET is not set
+CONFIG_DM=y
 # CONFIG_MMC is not set
 CONFIG_FSL_USDHC=y
 CONFIG_USB=y
@@ -47,4 +48,5 @@ CONFIG_USB_GADGET_MANUFACTURER="FSL"
 CONFIG_USB_GADGET_VENDOR_NUM=0x0525
 CONFIG_USB_GADGET_PRODUCT_NUM=0xa4a5
 CONFIG_CI_UDC=y
-CONFIG_REGEX=y
+CONFIG_OF_LIBFDT=y
+# CONFIG_EFI_LOADER is not set