image: Load the correct configuration in fit_check_sign

At present bootm_host_load_images() is passed the configuration that has
been verified, but ignores it and just uses the default configuration.
This may not be the same.

Update this function to use the selected configuration.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/common/bootm.c b/common/bootm.c
index 902c138..db4362a 100644
--- a/common/bootm.c
+++ b/common/bootm.c
@@ -819,7 +819,8 @@
 #else /* USE_HOSTCC */
 
 #if defined(CONFIG_FIT_SIGNATURE)
-static int bootm_host_load_image(const void *fit, int req_image_type)
+static int bootm_host_load_image(const void *fit, int req_image_type,
+				 int cfg_noffset)
 {
 	const char *fit_uname_config = NULL;
 	ulong data, len;
@@ -831,6 +832,7 @@
 	void *load_buf;
 	int ret;
 
+	fit_uname_config = fdt_get_name(fit, cfg_noffset, NULL);
 	memset(&images, '\0', sizeof(images));
 	images.verify = 1;
 	noffset = fit_image_load(&images, (ulong)fit,
@@ -878,7 +880,7 @@
 	for (i = 0; i < ARRAY_SIZE(image_types); i++) {
 		int ret;
 
-		ret = bootm_host_load_image(fit, image_types[i]);
+		ret = bootm_host_load_image(fit, image_types[i], cfg_noffset);
 		if (!err && ret && ret != -ENOENT)
 			err = ret;
 	}