u-boot-compulab: Fix SPL crash with crc32 checks commit

CONFIG_CMD_HASH is injected by meta-balena
in UBOOT_VARS to fix build for other devices, but caused
the SPL to crash for this DT. Removing it makes the crc32
checks run fine and the SPL no longer crashes.

Signed-off-by: Alexandru Costache <alexandru@balena.io>

layers/meta-balena-imx8mm/recipes-bsp/u-boot/u-boot-compulab_2021.04.bbappend

@@ -51,6 +51,10 @@ do_configure () {
 
 BALENA_UBOOT_DEVICE_TYPES_prepend = " usb "
 
+# Fixes SPL crash with CRC32 checks PR in meta-balena.
+# CRC32 checks on kernel image and fdt run fine with the above.
+UBOOT_VARS_remove = "CONFIG_CMD_HASH"
+
 SRC_URI_append = " \
 	file://1127-Revert-remove-include-config_defaults.h.patch \
 	file://1128-Integrate-with-Balena-u-boot-environment.patch \