tools: kwbimage: Add constant for SDIO bootfrom

Add constant for SDIO value of the bootfrom header field.

Signed-off-by: Marek BehĂșn <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Chris Packham <judge.packham@gmail.com>
Tested-by: Chris Packham <judge.packham@gmail.com>
diff --git a/tools/kwbimage.h b/tools/kwbimage.h
index 0b6d05b..9856b44 100644
--- a/tools/kwbimage.h
+++ b/tools/kwbimage.h
@@ -27,6 +27,7 @@
 #define IBR_HDR_SATA_ID			0x78
 #define IBR_HDR_PEX_ID			0x9C
 #define IBR_HDR_UART_ID			0x69
+#define IBR_HDR_SDIO_ID			0xAE
 #define IBR_DEF_ATTRIB	 		0x00
 
 /* Structure of the main header, version 0 (Kirkwood, Dove) */