Update to latest SeaBIOS

 - 8f469b9 Dynamically allocate ata_channel info; introduce custom atadrive_s struct.
 - 575ffc8 Cleanup - build drive description in temp memory during init.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/pc-bios/bios.bin b/pc-bios/bios.bin
index 3f40700..7a8f0d0 100644
--- a/pc-bios/bios.bin
+++ b/pc-bios/bios.bin
Binary files differ
diff --git a/roms/seabios b/roms/seabios
index 0360e8e..8f469b9 160000
--- a/roms/seabios
+++ b/roms/seabios
@@ -1 +1 @@
-Subproject commit 0360e8e69bb3a773ceb9d2b091b62c027bca862b
+Subproject commit 8f469b9676127ba6bb52609d89ec774e61db0ee1