Synopsis: If speed of link between two devices is slower than the reported max speed of both endpoints, the current driver will fail and be unable to negotiate.
Synopsis:
If speed of link between two devices is slower than the reported max
speed of both endpoints, the current driver will fail and be unable to
negotiate.

Summary:
Test negotiated speed by reading the CSRROM into a dummy variable.
If that read fails, decrement our speed and retry.  If all else fails,
go to lowest speed possible(0).

Report speed to the user.
Add display of the Bus Info Block when debug.firewire_debug > 1
Support the Bus Info Block(1394a-2000) method of speed detection.

I also should note that I am moving "hold_count" to 0 for future
releases.

This variable determines how many bus resets to "hold" a removed
firewire device before deletion.  I don't feel this is useful and will
probably drop support for this sysctl in the future.

Reviewed by:    scottl(mentor)
MFC after:      2 weeks

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