shpchp: remove shpchprm_get_physical_slot_number

This patch removes unnecessary shpchprm_get_physical_slot_number()
function.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>