arm64: dts: imx8mp-phyboard-pollux-rdk: Add missing pinctrl entry

Add missing pinctrl-names for i2c gpio recovery mode.

Fixes: 88f7f6bc

 ("arm64: dts: freescale: Add support for phyBOARD-Pollux-i.MX8MP")
Signed-off-by: Teresa Remmet <t.remmet@phytec.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>