ARM: dts: r8a779x: Add '#reset-cells' in cpg-mssr

With the latest dtc, we get many warnings about the missing
'#reset-cells' property in these controllers, e.g.:

arch/arm/boot/dts/r8a7790-lager.dtb: Warning (resets_property): Missing property '#reset-cells' in node /clock-controller@e6150000 or bad phandle (referred from /can@e6e80000:resets[0])
arch/arm/boot/dts/r8a7792-blanche.dtb: Warning (resets_property): Missing property '#reset-cells' in node /soc/clock-controller@e6150000 or bad phandle (referred from /soc/dma-controller@e6700000:resets[0])
arch/arm/boot/dts/r8a7792-wheat.dtb: Warning (resets_property): Missing property '#reset-cells' in node /soc/clock-controller@e6150000 or bad phandle (referred from /soc/ethernet@e6800000:resets[0])
arch/arm/boot/dts/r8a7793-gose.dtb: Warning (resets_property): Missing property '#reset-cells' in node /clock-controller@e6150000 or bad phandle (referred from /gpio@e6050000:resets[0])
arch/arm/boot/dts/r8a7794-alt.dtb: Warning (resets_property): Missing property '#reset-cells' in node /clock-controller@e6150000 or bad phandle (referred from /i2c@e6500000:resets[0])
arch/arm/boot/dts/r8a7794-silk.dtb: Warning (resets_property): Missing property '#reset-cells' in node /clock-controller@e6150000 or bad phandle (referred from /interrupt-controller@e61c0000:resets[0])

This adds it for the three r8a779x chips that were lacking it. The
binding mandates this as <1>, so this is the value I use.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[geert: Add fix for r8a7793.dtsi]
Fixes: 34fbd2b1 ("ARM: dts: r8a7790: Add reset control properties")
Fixes: 6e11a322 ("ARM: dts: r8a7792: Add reset control properties")
Fixes: 84fb19e1 ("ARM: dts: r8a7793: Add reset control properties")
Fixes: 615beb75 ("ARM: dts: r8a7794: Add reset control properties")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>