boards: lpcxpresso55s36: Add USBFS support

1. Add support for USB Full Speed controller.
2. Enable USB VBUS pin via pinctrl.

Signed-off-by: Mahesh Mahadevan <mahesh.mahadevan@nxp.com>
diff --git a/boards/arm/lpcxpresso55s36/doc/index.rst b/boards/arm/lpcxpresso55s36/doc/index.rst
index 8e9e358..d25bf77 100644
--- a/boards/arm/lpcxpresso55s36/doc/index.rst
+++ b/boards/arm/lpcxpresso55s36/doc/index.rst
@@ -79,6 +79,8 @@
 +-----------+------------+-------------------------------------+
 | CSS       | on-chip    | entropy                             |
 +-----------+------------+-------------------------------------+
+| USB FS    | on-chip    | USB Full Speed device               |
++-----------+------------+-------------------------------------+
 
 Other hardware features are not currently enabled.
 
@@ -137,6 +139,8 @@
 +---------+-----------------+----------------------------+
 | PIO1_3  | CAN0_RXD        | CAN RX                     |
 +---------+-----------------+----------------------------+
+| PIO0_22 | USB0_VBUS       | USBFS VBUS                 |
++---------+-----------------+----------------------------+
 
 System Clock
 ============
diff --git a/boards/arm/lpcxpresso55s36/lpcxpresso55s36-pinctrl.dtsi b/boards/arm/lpcxpresso55s36/lpcxpresso55s36-pinctrl.dtsi
index 56787b9..2d68da1 100644
--- a/boards/arm/lpcxpresso55s36/lpcxpresso55s36-pinctrl.dtsi
+++ b/boards/arm/lpcxpresso55s36/lpcxpresso55s36-pinctrl.dtsi
@@ -113,5 +113,10 @@
 		};
 	};
 
-
+	pinmux_usbfs: pinmux_usbfs {
+		group0 {
+			pinmux = <USB0_VBUS_PIO1_31>;
+			slew-rate = "standard";
+		};
+	};
 };
diff --git a/boards/arm/lpcxpresso55s36/lpcxpresso55s36.dts b/boards/arm/lpcxpresso55s36/lpcxpresso55s36.dts
index e64f89b..7ac40ff 100644
--- a/boards/arm/lpcxpresso55s36/lpcxpresso55s36.dts
+++ b/boards/arm/lpcxpresso55s36/lpcxpresso55s36.dts
@@ -162,3 +162,9 @@
 	pinctrl-0 = <&pinmux_flexpwm1_pwm0>;
 	pinctrl-names = "default";
 };
+
+zephyr_udc0: &usbfs {
+	status = "okay";
+	pinctrl-0 = <&pinmux_usbfs>;
+	pinctrl-names = "default";
+};