arm64: Fixup __NR_* compat syscalls count.

Should have gone in the cherry-pick
  cfc7e99e9e3900056028a7d90072e9ea0d886f8d
   arm64: Add __NR_* definitions for compat syscalls

Change-Id: I69a69e4b1f206aad4ece1a8b06f9e23e99adcbfb