ARM: rmobile: Enable SCIFA0 early on H2 Stout

The H2 Stout uses SCIFA0 for serial console, make sure it is
available very early on when probing from DT.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>