dt-bindings: auxdisplay: ht16k33: Fix default-brightness-level range

V4 changed the range from 0..15 to 1..16 in the driver, to match the
dimming set hardware register, but forgot to update the DT binding
documentation.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Documentation/devicetree/bindings/display/ht16k33.txt

@@ -8,7 +8,7 @@ Required properties:
 
 Optional properties:
 - linux,no-autorepeat:	Disable keyrepeat.
-- default-brightness-level: Initial brightness level [0-15] (default: 15).
+- default-brightness-level: Initial brightness level [1-16] (default: 16).
 
 - Keypad
  Supply the 'interrupts' property to enable the keyscan feature.