pc-bios: update OpenBIOS images

Update OpenBIOS images to SVN r1056.
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

pc-bios/README

@@ -12,7 +12,7 @@
   1275-1994 (referred to as Open Firmware) compliant firmware.
   The included images for PowerPC (for 32 and 64 bit PPC CPUs),
   Sparc32 and Sparc64 are built from OpenBIOS SVN revision
-  1047.
+  1056.
 
 - SLOF (Slimline Open Firmware) is a free IEEE 1275 Open Firmware
   implementation for certain IBM POWER hardware.  The sources are at