Created new attribute lpfc_enable_mi, which by default is enabled.

Add command definition bits for SLI-4 parameters that recognize whether the
adapter has MIB information support and what revision of MIB data.  Using
the adapter information, register vendor-specific MIB support with FDMI.
The registration will be done every link up.

During FDMI registration, encountered a couple of errors when reverting to
FDMI rev1. Code needed to exist once reverting. Fixed these.

Link: https://lore.kernel.org/r/20201020202719.54726-8-james.smart@broadcom.comCo-developed-by: NDick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: NDick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: NJames Smart <james.smart@broadcom.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>