devicetree: fix base power supply-gpios

This should have been a phandle-array since it's a full GPIO specifier
including pin and flags.

Signed-off-by: Peter Bigot <[email protected]>

Author: pabigot

dts/bindings/base/power.yaml

@@ -5,7 +5,7 @@
 
 properties:
     supply-gpios:
-      type: phandle
+      type: phandle-array
       required: false
       description: |
         GPIO specifier that controls power to the device.