pseries: Update SLOF firmware image to qemu-slof-20140630

The changelog is:
  > Quieten the grub warning
  > Add boot menu support
  > boot from disk having chrp-boot file
  > fat16: fix read and remove debug messages
  > dhcparch define missing in compilation
  > pci-scan: reserve memory for pci-bridge without devices
  > pci-bridge: Fix ranges when no device beyond the bridge
  > Set dhcp arch in board-qemu config file
  > xhci: fix controller stop
  > dhcp: support client architecture code 93
  > virtio-blk: support variable block size
  > usb: use common pci dma alloc/mapping routines
  > Remove unused SLOF code
  > pci-bridge: generic bridge needs to support pci dma functions
  > pci: extract dma functions as separate file
  > e1000: fix usage of multiple nics

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alexander Graf <agraf@suse.de>