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>
diff --git a/common/spl/spl_usb.c b/common/spl/spl_usb.c
index 67d5030..ccf01c8 100644
--- a/common/spl/spl_usb.c
+++ b/common/spl/spl_usb.c
@@ -49,10 +49,10 @@
 
 #if CONFIG_IS_ENABLED(OS_BOOT)
 	if (spl_start_uboot() ||
-	    spl_load_image_fat_os(spl_image, stor_dev, partition))
+	    spl_load_image_fat_os(spl_image, bootdev, stor_dev, partition))
 #endif
 	{
-		err = spl_load_image_fat(spl_image, stor_dev, partition, filename);
+		err = spl_load_image_fat(spl_image, bootdev, stor_dev, partition, filename);
 	}
 
 	if (err) {