kernel: ocf: add missing dependency for hifn driver

The HIFN driver is a PCI driver, thus requires PCI support to be enabled
to compile. Therefore let it depend on PCI..

Should fix mvebu builds.

Signed-off-by: Jonas Gorski <jogo@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@39357 3c298f89-4303-0410-b956-a3cf2f4a3e73