[PATCH] com20020 build fix

com20020.c needs to export functions if either of the ISA or PCI modules
are built as loadable modules.  Or they could always be exported.

WARNING: "com20020_found" [drivers/net/arcnet/com20020-pci.ko] undefined!
WARNING: "com20020_check" [drivers/net/arcnet/com20020-pci.ko] undefined!

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Toralf Forster <toralf.foerster@gmx.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>