[PATCH] sis190: allow a non-hardcoded ID for the PHY.

Allow a non-hardcoded ID for the PHY

This is the first step before the driver probes for the PHY address.

Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>