MIPS: ath79: Fix compilation error when CONFIG_PCI is disabled
When CONFIG_PCI is disabled, 'db120_pci_init()' had a different
signature than when was enabled. Therefore, compilation failed when
CONFIG_PCI was not present.
arch/mips/ath79/mach-db120.c:132: error: too many arguments to function 'db120_pci_init'