perf tools: Fix build error for LoongArch

There exists the following error when building perf tools on LoongArch:

  CC      util/syscalltbl.o
In file included from util/syscalltbl.c:16:
tools/perf/arch/loongarch/include/syscall_table.h:2:10: fatal error: asm/syscall_table_64.h: No such file or directory
    2 | #include <asm/syscall_table_64.h>
      |          ^~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.

This is because the generated syscall header is syscalls_64.h rather
than syscall_table_64.h. The above problem was introduced from v6.14,
then the header syscall_table.h has been removed from mainline tree
in commit af472d3c44 ("perf syscalltbl: Remove syscall_table.h"),
just fix it only for the linux-6.14.y branch of stable tree.

By the way, no need to fix the mainline tree and there is no upstream
git id for this patch.

How to reproduce:

  git clone https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
  cd linux && git checkout origin/linux-6.14.y
  make JOBS=1 -C tools/perf

Fixes: fa70857a27 ("perf tools loongarch: Use syscall table")
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tools/perf/arch/loongarch/include/syscall_table.h

@@ -1,2 +1,2 @@
 /* SPDX-License-Identifier: GPL-2.0 */
-#include <asm/syscall_table_64.h>
+#include <asm/syscalls_64.h>