arm64: dts: renesas: r8a77961: Add CAN{0,1} placeholder nodes

With the same background and purpose as described in v4.20-rc1
commit 92bc66bf ("arm64: dts: renesas: r8a77965: Add CAN{0,1}
placeholder nodes"), add can0 and can1 placeholder nodes.

Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Link: https://lore.kernel.org/r/20201029133741.25721-1-erosca@de.adit-jv.com


Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>