serial: pch: Invoke handle_rx_to() directly.

handle_rx() is only a wrapper around handle_rx_to() without any
additional functionality.

Invoke handle_rx_to() directly and remove handle_rx().

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20240301215246.891055-14-bigeasy@linutronix.de


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