Support for Renesas Arm families was added in commit 1ff4f4df23
("armsr: armv8: enable CONFIG_ARCH_RENESAS"), but this did not
enable the console/tty hardware for these SoCs, which is derived
from the SuperH family (CONFIG_SERIAL_SH_SCI).
Link: https://github.com/openwrt/openwrt/issues/15284
Signed-off-by: Mathew McBride <matt@traverse.com.au>