fusee/exo: enum support for 15.0.0

fusee/program/source/fusee_setup_horizon.cpp

@@ -253,6 +253,8 @@ namespace ams::nxboot {
                         return ams::TargetFirmware_13_2_1;
                     } else if (std::memcmp(package1 + 0x10, "20220209", 8) == 0) {
                         return ams::TargetFirmware_14_0_0;
+                    } else if (std::memcmp(package1 + 0x10, "20220801", 8) == 0) {
+                        return ams::TargetFirmware_15_0_0;
                     }
                     break;
                 default: