Add the missing fifth interrupt to the device node that represents the
ARM architected timer.  While at it, add an interrupt-names property for
clarity,

Fixes: 7c2b8198 ("arm64: dts: renesas: Add initial DTSI for RZ/V2L SoC")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/834244e77e5f407ee6fab1ab5c10c98a8a933085.1718890849.git.geert+renesas@glider.be