Add tvOS to build script

[simlay]

When trying to dig into the issues I'm seeing with rust-lang/rust#115773

This error:

  = note: ld: in ...libcompiler_builtins-dec41db284f76766.rlib(6a598989782b7c87-lse_cas1_relax.o), building for tvOS, but linking in object file built for macOS, file '...libcompiler_builtins-dec41db284f76766.rlib' for architecture arm64

Lead me to the this build.rs, while these changes haven't solved my issue, I feel like tvos should be in the same places as watchos and ios.