Remove vDSO support from make-syscall.sh

The auto-generated vDSO call shows some issues:

  - It requires sync the auto-generated C file with current glibc
    implementation;
  - It still uses symbol redirections hacks where libc-symbols.h
    provide macros that uses compiler builtins
    (libc_ifunc_redirected for instance);
  - It does not handle all required compiler handling
    (inhibit_stack_protector on iFUNC resolver).
  - No architecure uses it.

Checked with a build against all major ABIs.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>