sandbox: bootm: Don't fail the architecture check

Since sandbox is used for testing, it should be able to 'boot' an image
from any archhitecture. This allows us to test an image by loading it in
sandbox.

Signed-off-by: Simon Glass <sjg@chromium.org>

common/image-fit.c

@@ -1591,7 +1591,7 @@ int fit_image_load(bootm_headers_t *images, ulong addr,
 	}
 
 	bootstage_mark(bootstage_id + BOOTSTAGE_SUB_CHECK_ARCH);
-#ifndef USE_HOSTCC
+#if !defined(USE_HOSTCC) && !defined(CONFIG_SANDBOX)
 	if (!fit_image_check_target_arch(fit, noffset)) {
 		puts("Unsupported Architecture\n");
 		bootstage_error(bootstage_id + BOOTSTAGE_SUB_CHECK_ARCH);