The pci_ftpci_init() function is implemented
in 'drivers/pci/pci_ftpci100.c' however it is
always called by external code.

Add function declaration into ftpci100.h to
make it visible for external code.

Compile tested only.

Cc: Macpaul Lin <macpaul@andestech.com>
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>