ARM: dts: r8a7790: Add clocks for CA7 CPU cores

Currently only the CPU cores in the CA15 cluster have clocks properties.
Add the missing clocks properties for the CPU cores in the CA7 cluster
to fix this.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>