tools arch x86 uapi: Synch asm/unistd.h with the kernel sources

To pick up the change in:

  45e29d11 ("x86/syscalls: Make __X32_SYSCALL_BIT be unsigned long")

That doesn't trigger any changes in tooling and silences this perf build
warning:

  Warning: Kernel ABI header at 'tools/arch/x86/include/uapi/asm/unistd.h' differs from latest version at 'arch/x86/include/uapi/asm/unistd.h'
  diff -u tools/arch/x86/include/uapi/asm/unistd.h arch/x86/include/uapi/asm/unistd.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/arch/x86/include/uapi/asm/unistd.h

@@ -3,7 +3,7 @@
 #define _UAPI_ASM_X86_UNISTD_H
 
 /* x32 syscall flag bit */
-#define __X32_SYSCALL_BIT	0x40000000
+#define __X32_SYSCALL_BIT	0x40000000UL
 
 #ifndef __KERNEL__
 # ifdef __i386__