On some hardware designs where the 5V VBUS is fixed (always on) or cannot
be controlled by the FUSB302, the TCPM state machine may hang during the
transition to SRC_ATTACHED.

Normally, when TCPM instructs the driver to enable VBUS, it waits for a
VBUS_PRESENT signal from the port driver. However, if VBUS is already
physically present (because it's hardwired), the FUSB302 does not generate
a new interrupt or status change, causing the TCPM to time out waiting for
VBUS.

This patch introduces a new device property "fcs,force-vbus-toggle".
When set, the driver manually toggles the internal VBUS presence state
and notifies the TCPM during the VBUS enabling phase. This simulates a
VBUS rising edge, satisfying the state machine's requirement to proceed.

Signed-off-by: Jiali Chen <chenjiali@radxa.com>

Enable the FUSB302 USB Type-C controller on the Radxa Zero board.
The FUSB302 is connected via I2C3 and handles the CC communication.

Since the VBUS on this board is derived from the system 5V and cannot
be independently switched off or regulated to 0V, we configure the
node with specific properties to handle this hardware limitation:
- 'tcpm,skip-vsafe0v-check': To bypass the VSafe0V requirement.
- 'fcs,force-vbus-toggle': To simulate VBUS toggle for the TCPM state machine.

This patch also:
- Adds the fixed 5V VBUS regulator.
- Adds a GPIO-based SBU mux for orientation switching.
- Links the DWC3 USB controller to the Type-C connector via OF graph.
- Configures the port as a Source (Power) and Host (Data) by default.

Signed-off-by: Jiali Chen <chenjiali@radxa.com>

Add the device tree node for the green status LED found on the Radxa Zero.
The LED is connected to GPIOAO_10 and is configured to use the 'heartbeat'
trigger by default to indicate system activity.

Signed-off-by: Jiali Chen <chenjiali@radxa.com>