[SCSI] zfcp: Cleanup code in zfcp_erp.c

Cleanup the code in zfcp_erp.c, move erp internal definititions to
this file and move FSF timeout handling to the FSF layer.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>