arm64: dts: add pinctrl-single property for Stratix10/Agilex

The Stratix10/Agilex has a pin control IP that can make use of the
pinctrl-single driver.

Add the pinctrl-single dts property for the Stratix10/Agilex
platforms.

Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
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v2: no changes