ravb: Update DT binding example for final CPG/MSSR bindings

ravb: Update DT binding example for final CPG/MSSR bindings

The example in the DT binding documentation uses the preliminary DT
bindings for the r8a7795 MSTP clocks, which never went upstream.
Update the example to use the DT bindings for the upstream Clock Pulse
Generator / Module Standby and Software Reset hardware block.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>