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/include/bootsplash.h

@@ -12,7 +12,8 @@
  * and >0 on jpeg errors.
  */
 void set_bootsplash(unsigned char *framebuffer, unsigned int x_resolution,
-		    unsigned int y_resolution, unsigned int fb_resolution);
+		    unsigned int y_resolution, unsigned int bytes_per_line,
+		    unsigned int fb_resolution);
 
 
 void bmp_load_logo(uint32_t *logo_ptr, uint32_t *logo_size);