net: phy: micrel: remove redundant assignment to pointer of_node

The pointer of_node is being initialized with a value that is never
read and it is being updated later with a new value inside a do-while
loop. The initialization is redundant and can be removed and the
pointer dev is no longer required and can be removed too.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>