net: phy: Remove stale comments referencing timer

Since commit a390d1f3

 ("phylib: convert state_queue work to
delayed_work"), the PHYLIB state machine was converted to use delayed
workqueues, yet some functions were still referencing the PHY library
timer in their comments, fix that and remove the now unused
linux/timer.h include.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>