arm64: dts: renesas: r8a77990: Revise the cache controller node

The cache controller node should not have unit-addresses and reg
properties. So, this patch removes them.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>