Enable support for the IRQC on RZ/A1H, which is a small front-end to the
GIC.  This allows to use up to 8 external interrupts with configurable
sense select.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>