powerpc: mpc8572ds: Do not wrap pci_eth_init() with CONFIG_TSEC_ENET

The call to pci_eth_init() should not be wrapped with CONFIG_TSEC_ENET.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>