bootm: Reduce arguments to boot_get_fdt()

This function only uses one argument from bootm (argv[2]) so pass it in
directly.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/boot/bootm.c b/boot/bootm.c
index cd11994..5dc9cde 100644
--- a/boot/bootm.c
+++ b/boot/bootm.c
@@ -529,8 +529,9 @@
 		buf = map_sysmem(img_addr, 0);
 
 		/* find flattened device tree */
-		ret = boot_get_fdt(buf, flag, argc, argv, IH_ARCH_DEFAULT,
-				   &images, &images.ft_addr, &images.ft_len);
+		ret = boot_get_fdt(buf, argc > 2 ? argv[2] : NULL,
+				   IH_ARCH_DEFAULT, &images, &images.ft_addr,
+				   &images.ft_len);
 		if (ret) {
 			puts("Could not find a valid device tree\n");
 			return 1;
diff --git a/boot/image-fdt.c b/boot/image-fdt.c
index 6ff2d52..08fca08 100644
--- a/boot/image-fdt.c
+++ b/boot/image-fdt.c
@@ -447,19 +447,16 @@
 	return 0;
 }
 
-int boot_get_fdt(void *buf, int flag, int argc, char *const argv[], uint arch,
+int boot_get_fdt(void *buf, const char *select, uint arch,
 		 struct bootm_headers *images, char **of_flat_tree,
 		 ulong *of_size)
 {
-	ulong		fdt_addr;
-	char		*fdt_blob = NULL;
-	const char *select = NULL;
+	char *fdt_blob = NULL;
+	ulong fdt_addr;
 
 	*of_flat_tree = NULL;
 	*of_size = 0;
 
-	if (argc > 2)
-		select = argv[2];
 	if (select || genimg_has_config(images)) {
 		int ret;
 
diff --git a/include/image.h b/include/image.h
index a4555f2..04f35de 100644
--- a/include/image.h
+++ b/include/image.h
@@ -812,8 +812,7 @@
  * boot_get_fdt() - locate FDT devicetree to use for booting
  *
  * @buf: Pointer to image
- * @argc: command argument count
- * @argv: command argument list
+ * @select: FDT to select (this is normally argv[2] of the bootm command)
  * @arch: architecture (IH_ARCH_...)
  * @images: pointer to the bootm images structure
  * @of_flat_tree: pointer to a char* variable, will hold fdt start address
@@ -832,7 +831,7 @@
  *     1, if fdt image is found but corrupted
  *     of_flat_tree and of_size are set to 0 if no fdt exists
  */
-int boot_get_fdt(void *buf, int flag, int argc, char *const argv[], uint arch,
+int boot_get_fdt(void *buf, const char *select, uint arch,
 		 struct bootm_headers *images, char **of_flat_tree,
 		 ulong *of_size);