arm64: dts: renesas: Add interrupt-names to CANFD nodes

The Renesas R-Car CAN-FD Controller on R-Car Gen3 and RZ/G2 SoCs has two
interrupts.  Add interrupt-names properties to all CAN-FD device nodes
to identify the individual interrupts, so we can make this property a
required property in the DT bindings.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/10eef1e20372af4a156b06df8e5124666ec7c6b6.1651512451.git.geert+renesas@glider.be