sparc64/PCI: drop PCI_CACHE_LINE_BYTES

sparc64 is now the only user of PCI_CACHE_LINE_BYTES.  Drop it and set
pci_dfl_cache_line_size from pcibios_init() instead and drop
PCI_CACHE_LINE_BYTES handling from generic pci code.

Orignally-From: David Miller <davem@davemloft.net>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>