serial: sh-sci: Add DT support for dedicated RTS/CTS

Add support for indicating the availability of dedicated lines for
RTS/CTS hardware flow control, using the standard "uart-has-rtscts" DT
property.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/sh-sci.c

@@ -2999,6 +2999,9 @@ sci_parse_dt(struct platform_device *pdev, unsigned int *dev_id)
 	p->regtype = SCI_OF_REGTYPE(match->data);
 	p->scscr = SCSCR_RE | SCSCR_TE;
 
+	if (of_find_property(np, "uart-has-rtscts", NULL))
+		p->capabilities |= SCIx_HAVE_RTSCTS;
+
 	return p;
 }