Consider unsupported platforms as exotic

Only fall back on Linuxx64 on platforms not mentioned in
5bfc75d92e/tools/perf/scripts/python/Perf-Trace-Util/lib/Perf/Trace/Util.py (L56)
(excluding the i*86 platforms)

src/main/bash/sdkman-init.sh

@@ -63,6 +63,9 @@ function infer_platform() {
 	  aarch64)
 		echo "LinuxARM64"
 		;;
+	  alpha | i64 | ppc | ppc64le | ppc64el | s390 | s390x)
+		echo "exotic"
+		;;
 	  *)
 	  	echo "LinuxX64"
 	  	;;