This patch adds pin control for HSCIF1, and supports connection with
Debug Serial-1 (CN26) on Salvator boards.

SCIF1 and HSCIF1 are sharing the pins connected to Debug Serial-1 (CN26)
on Salvator boards, and it is necessary to ensure that either SCIF1 or
HSCIF1 is enabled, not both.

As for the default of this DeviceTree, SCIF1 is connected.
Signed-off-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com>
Signed-off-by: Takeshi Kihara <takeshi.kihara.df@renesas.com>
[geert: Add missing "uart-has-rtscts"]
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>