This module requires pci_if.h, add it to the SRCS list.

We haven't noticed that it was missing because eisa has been disabled for
a while in -current, but it became apparent when some parallel-build stuff
was MFC'd to 10-stable and this module failed to build there.
Include two headers to provide prototype for modfind(2) and kldload(2).

MFC after:	2 weeks