Center bootsplash on bigger framebuffers

In the JPEG decoder, use `bytes_per_line` instead of `width` for
address calculations, to allow for bigger framebuffers. When
calling jpeg_decode(), add an offset to the framebuffer address
so the picture gets centered.

Change-Id: I0174bdccfaad425e708a5fa50bcb28a1b98a23f7
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/76424
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin L Roth <gaumless@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Reviewed-by: Subrata Banik <subratabanik@google.com>

src/lib/jpeg.h

@@ -31,8 +31,7 @@ struct jpeg_decdata {
 	int dquant[3][64];
 };
 
-int jpeg_decode(unsigned char *, unsigned char *, int, int, int,
-	struct jpeg_decdata *);
+int jpeg_decode(unsigned char *, unsigned char *, int, int, int, int, struct jpeg_decdata *);
 void jpeg_fetch_size(unsigned char *buf, int *width, int *height);
 int jpeg_check_size(unsigned char *, int, int);