MFP4: Move default setting to the end of isp_reset instead of the

MFP4: Move default setting to the end of isp_reset instead of the
front of isp_init so we can read NVRAM even if we're role ISP_NONE.
Prepare for reintroduction of channels (for FC) for N-Port
Virtualization.

Fix a botch in handle assignment that caused us to nuke one device
when a new one arrives and end up with two devices with the same
identity in the virtual target mapping table.