ARM: dts: stm32: Rename stmfx joystick pins on stm32mp157c-ev1

Rename stmfx joystick pins names according to yaml description.
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

arch/arm/boot/dts/stm32mp157c-ev1.dts

@@ -219,7 +219,7 @@ stmfx_pinctrl: pinctrl {
 			#interrupt-cells = <2>;
 			gpio-ranges = <&stmfx_pinctrl 0 0 24>;
 
-			joystick_pins: joystick {
+			joystick_pins: joystick-pins {
 				pins = "gpio0", "gpio1", "gpio2", "gpio3", "gpio4";
 				bias-pull-down;
 			};