serial: sifive: Remove 0 from fu540-c000-uart0 binding.

The driver is using "sifive,fu540-c000-uart0" as a binding. The device
tree and documentation states "sifive,fu540-c000-uart" instead. This
means the binding is not matched and not used.

This did not cause any problems because the alternative binding, used in
the device tree, "sifive,uart0" is not handling the hardware any
different.

Align the binding in the driver with the documentation.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240307090950.eLELkuyK@linutronix.de


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>