Add OpenBIOS as a submodule

Update OpenBIOS images to r1047 built from submodule.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

.gitmodules

@@ -10,3 +10,6 @@
 [submodule "roms/ipxe"]
 	path = roms/ipxe
 	url = git://git.qemu.org/ipxe.git
+[submodule "roms/openbios"]
+	path = roms/openbios
+	url = git://git.qemu.org/openbios.git

pc-bios/README

@@ -10,9 +10,9 @@
 - OpenBIOS (http://www.openbios.org/) is a free (GPL v2) portable
   firmware implementation. The goal is to implement a 100% IEEE
   1275-1994 (referred to as Open Firmware) compliant firmware.
-  The included image for PowerPC (for 32 and 64 bit PPC CPUs)
+  The included images for PowerPC (for 32 and 64 bit PPC CPUs),
-  is built from OpenBIOS SVN revision 1044 and Sparc32 and Sparc64
+  Sparc32 and Sparc64 are built from OpenBIOS SVN revision
-  images are built from OpenBIOS SVN revision 1045.
+  1047.
 
 - SLOF (Slimline Open Firmware) is a free IEEE 1275 Open Firmware
   implementation for certain IBM POWER hardware.  The sources are at