board: frdm_mcxn236: Enable MICFIL on frdm_mcxn236

1. Enable MICFIL on frdm_mcxn236 board.
2. MICFIL CLOCK and DATA Pins are conflict with
flexcomm0_lpuart pins, so change flexcomm0_lpuart
pins to 'FC0_P2_PIO0_6' and 'FC0_P3_PIO0_7'.

Signed-off-by: Zhaoxiang Jin <[email protected]>

Author: ZhaoxiangJin

boards/nxp/frdm_mcxn236/frdm_mcxn236-pinctrl.dtsi

@@ -243,4 +243,14 @@
 			input-enable;
 		};
 	};
+
+	pinmux_micfil: pinmux_micfil {
+		group0 {
+			pinmux = <PDM0_CLK_PIO0_16>,
+				 <PDM0_DATA0_PIO0_17>;
+			drive-strength = "high";
+			slew-rate = "fast";
+			input-enable;
+		};
+	};
 };