SPL: Add struct spl_boot_device parameter into spl_parse_board_header()

Add parameter spl_boot_device to spl_parse_board_header(), which allows
the implementations to see from which device we are booting and do
boot-device-specific checks of the image header.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>

common/spl/spl_ram.c

@@ -70,7 +70,7 @@ static int spl_ram_load_image(struct spl_image_info *spl_image,
 		}
 		header = (struct image_header *)map_sysmem(u_boot_pos, 0);
 
-		spl_parse_image_header(spl_image, header);
+		spl_parse_image_header(spl_image, bootdev, header);
 	}
 
 	return 0;