ARM: dts: lan966x: rename pinctrl nodes

The pinctrl device tree binding will be converted to YAML format. Rename
the pin nodes so they end with "-pins" to match the schema.

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220420194230.3415663-1-michael@walle.cc


Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>