riscv: dts: renesas: Convert isa detection to new properties

Convert the RZ/Five devicetrees to use the new properties
"riscv,isa-base" & "riscv,isa-extensions".
For compatibility with other projects, "riscv,isa" remains.
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20231009-smog-gag-3ba67e68126b@wendySigned-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

arch/riscv/boot/dts/renesas/r9a07g043f.dtsi

@@ -24,6 +24,10 @@ cpu0: cpu@0 {
 			reg = <0x0>;
 			status = "okay";
 			riscv,isa = "rv64imafdc";
+			riscv,isa-base = "rv64i";
+			riscv,isa-extensions = "i", "m", "a", "f", "d", "c",
+					       "zicntr", "zicsr", "zifencei",
+					       "zihpm";
 			mmu-type = "riscv,sv39";
 			i-cache-size = <0x8000>;
 			i-cache-line-size = <0x40>;