ARM: dts: meson8: align OPP table names with DT schema

DT schema expects names of operating points tables to match certain
pattern:

meson8-minix-neo-x8.dtb: gpu-opp-table: $nodename:0: 'gpu-opp-table' does not match '^opp-table(-[a-z0-9]+)?$'

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Neil Armstrong <[e-mail]>

arch/arm/boot/dts/meson8.dtsi

···
 		};
 	};
 
-	gpu_opp_table: gpu-opp-table {
+	gpu_opp_table: opp-table-gpu {
 		compatible = "operating-points-v2";
 
 		opp-182142857 {

arch/arm/boot/dts/meson8b.dtsi

···
 		};
 	};
 
-	gpu_opp_table: gpu-opp-table {
+	gpu_opp_table: opp-table-gpu {
 		compatible = "operating-points-v2";
 
 		opp-255000000 {