ARM: dts: imx6: phycore-som: add da9062 gpio support

The pmic is a mfd device and supports gpios. Those gpios are not routed
to the SoM baseboard pin header but they are connected to the i.MX6. We
need the GPIO's to configure the pmic to select between the
suspend/resume arm and soc voltages

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>