arm64: dts: renesas: r8a779{7|8}0: move CAN clock node

The CAN clock node should precede the "cpus" node in the R8A779{7|8}0
device  trees,  according to  the alphanumeric node sorting rule...

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>