regulator: mt6315-regulator: fix invalid allowed mode

In the binding example, the regulator mode 4 is shown as a valid mode,
but the driver actually only support mode 0 to 2:

This generates an error in dmesg when copy/pasting the binding example:
[    0.306080] vbuck1: invalid regulator-allowed-modes element 4
[    0.307290] vbuck2: invalid regulator-allowed-modes element 4

This commit fixes this error by removing the invalid mode from the
examples.

Fixes: 977fb5b5 ("regulator: document binding for MT6315 regulator")
Signed-off-by: Fabien Parent <fparent@baylibre.com>
Link: https://lore.kernel.org/r/20220529154613.337559-1-fparent@baylibre.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/regulator/mt6315-regulator.yaml

@@ -55,7 +55,7 @@ examples:
           regulator-min-microvolt = <300000>;
           regulator-max-microvolt = <1193750>;
           regulator-enable-ramp-delay = <256>;
-          regulator-allowed-modes = <0 1 2 4>;
+          regulator-allowed-modes = <0 1 2>;
         };
 
         vbuck3 {
@@ -63,7 +63,7 @@ examples:
           regulator-min-microvolt = <300000>;
           regulator-max-microvolt = <1193750>;
           regulator-enable-ramp-delay = <256>;
-          regulator-allowed-modes = <0 1 2 4>;
+          regulator-allowed-modes = <0 1 2>;
         };
       };
     };