ARM: dts: stm32: cosmetic updates in stm32mp15-pinctrl

Use tabs where possible and remove multiple blanks lines.
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

arch/arm/boot/dts/stm32mp15-pinctrl.dtsi

@@ -1072,7 +1072,6 @@ pins {
 		};
 	};
 
-
 	sai2a_pins_b: sai2a-1 {
 		pins1 {
 			pinmux = <STM32_PINMUX('I', 6, AF10)>,	/* SAI2_SD_A */