sparc64: Fix missing devices due to PCI bridge test in of_create_pci_dev().

Just like in the arch/sparc64/kernel/of_device.c code fix commit
071d7f4c3b411beae08d27656e958070c43b78b4 ("sparc64: Fix SMP bootup
with CONFIG_STACK_DEBUG or ftrace.") we have to check the OF device
node name for "pci" instead of relying upon the 'device_type' property
being there on all PCI bridges.

Tested by Meelis Roos, and confirmed to make the PCI QFE devices
reappear on the E3500 system.

Signed-off-by: David S. Miller <davem@davemloft.net>