ARM: at91/dts: add macb mii pinctrl config for kizbox

This patch overrides default macb pinctrl config defined in
at91sam9260.dtsi (pinctrl_macb_rmii) with kizbox board config
(pinctrl_macb_rmii + pinctrl_macb_rmii_mii_alt).

Signed-off-by: Boris BREZILLON <linux-arm@overkiz.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>