tools: zynqmpimage: Align image_size/image_stored_size

Bootrom is not capable to work with non aligned bootloader sizes.
SPL with OF_SEPARATE generates non-align images quite often that's
why this change is required before OF_SEPARATE enableding.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/tools/zynqmpbif.c b/tools/zynqmpbif.c
index a33c15e..8c47107 100644
--- a/tools/zynqmpbif.c
+++ b/tools/zynqmpbif.c
@@ -425,8 +425,8 @@
 		if (!bif_output.header->image_offset)
 			bif_output.header->image_offset =
 				cpu_to_le32(bf->offset);
-		bif_output.header->image_size = cpu_to_le32(len);
-		bif_output.header->image_stored_size = cpu_to_le32(len);
+		bif_output.header->image_size = cpu_to_le32(len_padded);
+		bif_output.header->image_stored_size = cpu_to_le32(len_padded);
 
 		bif_output.header->image_attributes &= ~HEADER_CPU_SELECT_MASK;
 		switch (bf->dest_cpu) {