Only return HVX vector size on Hexagon targets.
Only return HVX vector size on Hexagon targets.


Former-commit-id: 945e977d9c8b17c8ddeadceec1d70cb25a36151a
Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide