realtek: Add support for detecting RTL9303 SoCs

Adds support for detecting RTL9303 SoCs as found e.g.
in the Ubiquiti USW switch.

Signed-off-by: Birger Koblitz <git@birger-koblitz.de>

target/linux/realtek/files-5.10/arch/mips/rtl838x/prom.c

@@ -170,6 +170,10 @@ void __init prom_init(void)
 		identify_rtl9302();
 		soc_info.family = RTL9300_FAMILY_ID;
 		break;
+	case 0x9303:
+		soc_info.name = "RTL9303";
+		soc_info.family = RTL9300_FAMILY_ID;
+		break;
 	case 0x9313:
 		soc_info.name = "RTL9313";
 		soc_info.family = RTL9310_FAMILY_ID;