pseries: Update SLOF firmware image to qemu-slof-20140304

The changelog is:
  > version: update to 20140304
  > Introduce dummy console device
  > vio-vscsi: Fix CRQ allocation alignment
  > version: update to 20140204
  > virtio-9p: disable unused structure
  > Make "boot net:dhcp" boot from IPv4 only
  > Fix virtio device shutdown
  > Change shutdown method name for virtio-scsi
  > Add support for 64bit LE ABI v1 and v2 support
  > Change representation of string environment variable
  > cas: return error when unknown node found
  > version: update
  > Reset obp-tftp arguments before parsing
  > Enable seamless netboot on IPv6 network
  > Fix shutdown for virtio devices
  > Fix zero checksum in UDP header
  > Handle router advertisement message properly
  > [oex]hci_exit: Check before freeing/unmapping memory
  > Work around missing sc 1 traps on pHyp
  > fix print_version() to return where it came from
  > usb-xhci: memory freeing and using returns as bool uniformly
  > Output banner and initial display output in VNC window
  > use VERSION file to generate FW version
  > cas: remove warning
  > Add support for loading little endian ELF binaries.
  > Add bswap_{16,32,64}p
  > dhcpv6 and other minor net-snk fixes
  > Fix missing drop in virtio-fs setup-alias
  > Find next available alias name
  > SLOF does not exit if given 1KB disk
  > boot: enable support for bootindex
  > pci-properties: add properties to enable hotplug for spapr
  > e1000: remember node handle
  > Increase quiesce tokens array size
  > virtio: timeout after 5sec
  > Enable IPv6 support in dns
  > usb-ohci: fix warnings
  > Add ipv6 support in net-snk
  > ipv4: fix frame overwriting following arp_send_request
  > e1000: fix SLOF_dma_map_out arguments
  > Maintain single global packet buffer for tftp
  > Increase virtio-net receive queue size
  > Increase veth receive queue size
  > Fix dprintf macros at various points
  > usb-ohci: rewrite done_head processing code
  > boot: add net in default boot order
  > block 0 address in the allocator
  > scsi: make-media-alias fix
  > usb-xhci: add xhci host controller support
  > usb-xhci: add xhci support
  > Avoid veth read/write calls with zero length buffer
  > boot: include other aliases
  > usb-core: disable xhci

Cc: Andreas Färber <afaerber@suse.de>
Cc: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>

pc-bios/README

@@ -17,7 +17,7 @@
 - SLOF (Slimline Open Firmware) is a free IEEE 1275 Open Firmware
   implementation for certain IBM POWER hardware.  The sources are at
   https://github.com/aik/SLOF, and the image currently in qemu is
-  built from git tag qemu-slof-20131015.
+  built from git tag qemu-slof-20140304.
 
 - sgabios (the Serial Graphics Adapter option ROM) provides a means for
   legacy x86 software to communicate with an attached serial console as