pci_eth_init() is already conditional to CONFIG_PCI so not every caller
needs to have conditionals.

This is the only place in the current code base where such a check is
still at the calling site.
Signed-off-by: NDetlev Zundel <dzu@denx.de>
CC: Ben Warren <biggerbadderben@gmail.com>
CC: Peter Pearse <peter.pearse@arm.com>