fnic: fnic Control Path Trace Utility

Fnic Ctlr Path Trace utility is a tracing functionality built directly into fnic
driver to trace the control path frames like discovery, FLOGI request/reply,
PLOGI request/reply, link event etc.  It will be one trace file for all fnics.
It will help us to debug and resolve the discovery and initialization related
issues in more convenient way. This trace information includes time stamp,
Host Number, Frame type, Frame Length and Frame. By default,64 pages are
allocated but we can change the number of allocated pages by module parameter
fnic_fc_trace_max_page. Each entry is of 256 byte and available entries are
depends on allocated number of pages. We can turn on or off the fnic control
path trace functionality by module paramter fc_trace_enable and/or reset the
trace contain by module paramter fc_trace_clear.

Signed-off-by: Hiral Shah <hishah@cisco.com>
Signed-off-by: Sesidhar Baddela <sebaddel@cisco.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>