net: phy: handle state correctly in phy_stop_machine

If the PHY is halted on stop, then do not set the state to PHY_UP.  This
ensures the phy will be restarted later in phy_start when the machine is
started again.

Fixes: 00db8189 ("This patch adds a PHY Abstraction Layer to the Linux Kernel, enabling ethernet drivers to remain as ignorant as is reasonable of the connected PHY's design and operation details.")
Signed-off-by: Nathan Sullivan <nathan.sullivan@ni.com>
Signed-off-by: Brad Mouring <brad.mouring@ni.com>
Acked-by: Xander Huff <xander.huff@ni.com>
Acked-by: Kyle Roeschley <kyle.roeschley@ni.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>