Allow force and force_via686a parameters. Driver will take the
address and program the base address in the 686a.
This is NOT a PCI force; the 3057 device must
be present in lspci.
Should work for Asus A7V/K7V boards which don't set the
base address (because they also have a as99127f on them!??).
Some rough edges remain, because
via686a_find() does not know there is a force; that only
is apparent to via686a_detect().
Notably, the driver will stay loaded even if the address is
uninitialized and there is no force; also, the driver complains
that a force is needed even when you give it one.