arm64: dts: renesas: Add missing opp-suspend properties

Tag the highest "Power Optimized" (1.5 GHz) Cortex-A57 operating point
table entries for the RZ/G2M, R-Car M3-W and M3-W+ SoCs with the
"opp-suspend" property.  This makes sure the system will enter suspend
in the same performance state as it will be resumed by the firmware
later, avoiding state inconsistencies after resume.

Based on a patch for R-Car M3-W in the BSP by Takeshi Kihara
<takeshi.kihara.df@renesas.com>.

Fixes: 800037e8 ("arm64: dts: renesas: r8a774a1: Add operating points")
Fixes: da7e3113 ("arm64: dts: renesas: r8a7796: Add OPPs table for cpu devices")
Fixes: f51746ad

 ("arm64: dts: renesas: Add Renesas R8A77961 SoC support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/r/45a061c3b0463aac7d10664f47c4afdd999da50d.1619699721.git.geert+renesas@glider.be