arm64: dts: amlogic: meson-g12: Fix GPU operating point table node name

Starting with commit 94274f20f6 ("dt-bindings: opp: Convert to DT
schema") the opp node name has a mandatory pattern. This change
fixes the dtbs_check warning:
gpu-opp-table: $nodename:0: 'gpu-opp-table' does not match
'^opp-table(-[a-z0-9]+)?$'
Put the 'gpu' part at the end to match the pattern.

Fixes: 916a0edc43 ("arm64: dts: amlogic: meson-g12: add the Mali OPP table and use DVFS")
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Alexander Stein <alexander.stein@mailbox.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20211026182813.900775-2-alexander.stein@mailbox.org

arch/arm64/boot/dts/amlogic/meson-g12-common.dtsi

@@ -58,7 +58,7 @@
 		secure-monitor = <&sm>;
 	};
 
-	gpu_opp_table: gpu-opp-table {
+	gpu_opp_table: opp-table-gpu {
 		compatible = "operating-points-v2";
 
 		opp-124999998 {