Create a new linker set, Xficl_compile_set which contains a list of
functions to call at the appropriate time to register new forth
words. In the past we've done this with ifdef soup, but now if the
file is included in the build, we'll get the new forth words.

Use this new functionality to move the pci bios stuff out of loader.c
by moving it to biospci.c.

Move the pnp functionality to common/pnp.c.

Move the inb/outb forth words to the i386 sysdep.c file where their
implementation is defined.

Adjust the efi linker scripts and build machinery to cope.

his should be an invisible change to forth scripts and user
experience.

Differential Revision: https://reviews.freebsd.org/D8145