serial: st-asc: fix typo in property name

Changes the property name read in the driver according to the YAML.
According to device-tree documentation, property names should not
include underscores.

Signed-off-by: Raphael Gallais-Pou <rgallaispou@gmail.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Message-ID: <20230604083558.16661-1-rgallaispou@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/st-asc.c

@@ -754,7 +754,7 @@ static struct asc_port *asc_of_get_asc_port(struct platform_device *pdev)
 
 	asc_ports[id].hw_flow_control = of_property_read_bool(np,
 							"uart-has-rtscts");
-	asc_ports[id].force_m1 =  of_property_read_bool(np, "st,force_m1");
+	asc_ports[id].force_m1 =  of_property_read_bool(np, "st,force-m1");
 	asc_ports[id].port.line = id;
 	asc_ports[id].rts = NULL;