seabios: update to e8a76b0f225bba5ba9d63ab227e0a37b3beb1059

This patch updates seabios to latest git master.  Changes:

  (1) q35 patches merged.
  (2) some acpi cleanups.
  (3) fixes irq 8 conflict.

(3) makes this a candidate for the stable branch

Cc: qemu-stable@nongnu.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>