arm64: dts: rockchip: fix pinctrl sleep nodename for rk3399.dtsi

A test with the command below aimed at powerpc generates
notifications in the Rockchip arm64 tree.

Fix pinctrl "sleep" nodename by renaming it to "suspend"
for rk3399.dtsi

make ARCH=arm64 dtbs_check
DT_SCHEMA_FILES=Documentation/devicetree/bindings/powerpc/sleep.yaml
Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Link: https://lore.kernel.org/r/20210126110221.10815-2-jbx6244@gmail.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/rk3399.dtsi

@@ -2354,7 +2354,7 @@ sdmmc_wp: sdmmc-wp {
 			};
 		};
 
-		sleep {
+		suspend {
 			ap_pwroff: ap-pwroff {
 				rockchip,pins = <1 RK_PA5 1 &pcfg_pull_none>;
 			};