[SCSI] hpsa: factor out hpsa_find_cfg_addrs.

Rationale for this is that I will also need to use this code
in fixing kdump host reset code prior to having the hba structure.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>