tools/kwbimage: add DEBUG option

Offset 0x1 in the generated kwb image file is a set of flags, bit 0
enables debug output from the BootROM firmware.  Allow a DEBUG option in
the kwb configuration to request debug output from the BootROM firmware.

Signed-off-by: Chris Packham <judge.packham@gmail.com>
Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/tools/kwbimage.h b/tools/kwbimage.h
index 9b06004..01c2f1f 100644
--- a/tools/kwbimage.h
+++ b/tools/kwbimage.h
@@ -73,7 +73,7 @@
 /* Structure of the main header, version 1 (Armada 370, Armada XP) */
 struct main_hdr_v1 {
 	uint8_t  blockid;               /* 0 */
-	uint8_t  reserved1;             /* 1 */
+	uint8_t  flags;                 /* 1 */
 	uint16_t reserved2;             /* 2-3 */
 	uint32_t blocksize;             /* 4-7 */
 	uint8_t  version;               /* 8 */