test_wamr.sh: Allow using test script on different platforms (#3098)

The `^^` for uppercase is not widely supported, e.g. not working on some MacOS M1.

tests/wamr-test-suites/test_wamr.sh

@@ -119,7 +119,7 @@ do
         ;;
         m)
         echo "set compile target of wamr" ${OPTARG}
-        TARGET=${OPTARG^^} # set target to uppercase if input x86_32 or x86_64 --> X86_32 and X86_64
+        TARGET=$(echo "$OPTARG" | tr '[a-z]' '[A-Z]') # set target to uppercase if input x86_32 or x86_64 --> X86_32 and X86_64
         ;;
         w)
         echo "enable WASI threads"