fdt: Update functions which write to an FDT to return -ENOSPC

When writing values into an FDT it is possible that there will be
insufficient space. If the caller gets a useful error then it can
potentially deal with the situation.

Adjust these functions to return -ENOSPC when the FDT is full.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/common/image-fit.c b/common/image-fit.c
index 77f32bc..732505a 100644
--- a/common/image-fit.c
+++ b/common/image-fit.c
@@ -833,7 +833,7 @@
  *
  * returns:
  *     0, on success
- *     -1, on property read failure
+ *     -ENOSPC if no space in device tree, -1 for other error
  */
 int fit_set_timestamp(void *fit, int noffset, time_t timestamp)
 {
@@ -847,7 +847,7 @@
 		printf("Can't set '%s' property for '%s' node (%s)\n",
 		       FIT_TIMESTAMP_PROP, fit_get_name(fit, noffset, NULL),
 		       fdt_strerror(ret));
-		return -1;
+		return ret == -FDT_ERR_NOSPACE ? -ENOSPC : -1;
 	}
 
 	return 0;