ARM: dts: at91: sam9_l9260: Add pinctrl information to ethernet node.

Add missing pinctrl information to ethernet node.

Signed-off-by: Raashid Muhammed <raashidmuhammed@zilogic.com>
Reviewed-by: Vijay Kumar B. <vijaykumar@bravegnu.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>