tracing: Document HAVE_SYSCALL_TRACEPOINTS needs
tracing: Document HAVE_SYSCALL_TRACEPOINTS needs

Document the arch needed requirements to get the support for syscalls
tracing.

v2: HAVE_FTRACE_SYSCALLS have been changed to HAVE_SYSCALL_TRACEPOINTS
    recently. Update this config name in the documentation then.

Signed-off-by: Frederic Weisbecker <e8a1bf9163cb25e93cfd6540f223b3872ea7ee55@gmail.com>
Acked-by: Heiko Carstens <8dcf0f69152f32f23184f83357a3731522e56b9c@de.ibm.com>
Cc: Ingo Molnar <9dbbbf0688fedc85ad4da37637f1a64b8c718ee2@elte.hu>
Cc: Steven Rostedt <43232e92d70cc7aa53504ad0397085ee47bad87f@goodmis.org>
Cc: Li Zefan <5dc16b054e85ffba6c8d314d8e55ae95dcab12a5@cn.fujitsu.com>
Cc: Masami Hiramatsu <308c3db2ad395e67f502db11a9ceb1603d4442e0@redhat.com>
Cc: Jason Baron <af9bd1db766a43cb09b647251c97dbddcd2e59dc@redhat.com>
Cc: Lai Jiangshan <4c9eb49378914b743bdd32292c04df29b820d73e@cn.fujitsu.com>
Cc: Martin Schwidefsky <52616596d8f5df0d597e85ab515377f92f939c68@de.ibm.com>
Cc: Paul Mundt <38b52dbb5f0b63d149982b6c5de788ec93a89032@linux-sh.org>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs