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>
diff --git a/common/image-fit.c b/common/image-fit.c
index 255c4ca..2b9e71a 100644
--- a/common/image-fit.c
+++ b/common/image-fit.c
@@ -1591,7 +1591,7 @@
 	}
 
 	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);