dt-bindings: interrupt-controller: renesas,r9a09g077-icu: Fix reg size in example

dt-bindings: interrupt-controller: renesas,r9a09g077-icu: Fix reg size in example

According to Figure 5.1 ("Unified memory map"), the safety register
block is 64 KiB large, just like the non-safety register block.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://patch.msgid.link/364ff570c8a1845fab24bd89557f06c9e406f8de.1781105007.git.geert+renesas@glider.be
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>