perf: script: prefer capstone to XED

Now perf can show assembly instructions with libcapstone for x86, and the
capstone is better in general.

Signed-off-by: Changbin Du <changbin.du@huawei.com>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: changbin.du@gmail.com
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240217074046.4100789-6-changbin.du@huawei.com