colibri-imx8x: enable i.MX specific BOOTAUX

commit e8cd1f60d964 ("imx: imx8: bootaux: Add i.MX8 M4 boot support")
implemented IMX_BOOTAUX. Enable it.

Signed-off-by: Andrejs Cainikovs <andrejs.cainikovs@toradex.com>
Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
diff --git a/configs/colibri-imx8x_defconfig b/configs/colibri-imx8x_defconfig
index e76373e..71a05b7 100644
--- a/configs/colibri-imx8x_defconfig
+++ b/configs/colibri-imx8x_defconfig
@@ -13,6 +13,7 @@
 CONFIG_BOOTAUX_RESERVED_MEM_BASE=0x88000000
 CONFIG_BOOTAUX_RESERVED_MEM_SIZE=0x08000000
 CONFIG_TARGET_COLIBRI_IMX8X=y
+CONFIG_IMX_BOOTAUX=y
 CONFIG_OF_LIBFDT_OVERLAY=y
 CONFIG_SYS_LOAD_ADDR=0x95c00000
 CONFIG_SYS_MEMTEST_START=0x88000000