ARM: dts: lager: use generic pinctrl properties

Since 16ccaf5b ("pinctrl: sh-pfc: Accept standard function, pins and
groups properties") renesas pfc drivers accept generic "function", "pins"
and "groups" properties.

This patch updates the lager device tree to use the generic
rather than renesas-specific properties.

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>