firewire: ohci: TSB41BA3D support tweaks

Fix:  phy_reg_mutex must be held over the write/read_phy_reg pair which
gets PHY port status.

Only print to the log when a TSB41BA3D was found.  By far most TSB82AA2
cards have a TSB81BA3, and firewire-ohci can keep quiet about that.

Shorten some strings and comments.  Change some whitespace.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>