[builtins][ARM] re-enable mulsc3_test.c on Arm
The mulsc3_test.c was marked as unsupported due to PR32457, the underlying
cause of this PR was fixed in PR28164 so we can remove the unsupported as
it is no longer needed.
// RUN: %clang_builtins %s %librt -lm -o %t && %run %t
-// UNSUPPORTED: armhf-target-arch
-// see pr 32475.
//===-- mulsc3_test.c - Test __mulsc3 -------------------------------------===//
//
// The LLVM Compiler Infrastructure
