On the BOCK-W development board, the RTS and CTS pins of the console
SCIF0 are wired to the "product serial" connector.  Reflect this in the
DTS by adding the "uart-has-rtscts" property to the scif0 device node.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>