tools: fix imximage warning

Fix build warning:

Configuring for MPC837XEMDS board...
imximage.c: In function `imximage_parse_cfg_file':
imximage.c:146: warning: passing argument 2 of `getline' from incompatible pointer type
/usr/include/bits/stdio.h:116: note: expected `size_t *' but argument is of type `uint32_t *'

Signed-off-by: Kim Phillips <kim.phillips@freescale.com>

tools/imximage.c

@@ -129,7 +129,7 @@ static uint32_t imximage_parse_cfg_file(struct imx_header *imxhdr, char *name)
 	char *token, *saveptr1, *saveptr2;
 	int lineno = 0;
 	int fld, value;
-	uint32_t len;
+	size_t len;
 	int dcd_len = 0;
 	dcd_t *dcd = &imxhdr->dcd_table;
 	int32_t cmd;