dt-bindings: usb: ohci: Increase the number of PHYs

"make dtbs_check":

    arch/arm/boot/dts/r8a77470-iwg23s-sbc.dtb: usb@ee080000: phys: [[17, 0], [31]] is too long
	    From schema: Documentation/devicetree/bindings/usb/generic-ohci.yaml
    arch/arm/boot/dts/r8a77470-iwg23s-sbc.dtb: usb@ee0c0000: phys: [[17, 1], [33], [21, 0]] is too long
	    From schema: Documentation/devicetree/bindings/usb/generic-ohci.yaml

Some USB OHCI controllers (e.g. on the Renesas RZ/G1C SoC) have multiple
PHYs.  Increase the maximum number of PHYs to 3, which is sufficient for
now.

Fixes: 0499220d ("dt-bindings: Add missing array size constraints")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/0112f9c8881513cb33bf7b66bc743dd08b35a2f5.1655301203.git.geert+renesas@glider.beSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/usb/generic-ohci.yaml

@@ -103,7 +103,8 @@ properties:
       Overrides the detected port count
 
   phys:
-    maxItems: 1
+    minItems: 1
+    maxItems: 3
 
   phy-names:
     const: usb