ISAPNP: pull pnp_add_card_id() out of isapnp_parse_card_id()

Split the pnp_add_card_id() part from the PNPID conversion part so we
can move the initial add_id() into the pnp_card allocation.

This makes the PNPID conversion generic so we can use the same
one for both devices and cards.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-By: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>