As specified by ftrace-design.txt, TIF_SYSCALL_TRACEPOINT was
added, as well as NR_syscalls in asm/unistd.h.  Additionally,
__sys_trace was modified to call trace_sys_enter and
trace_sys_exit when appropriate.

Tests #2 - #4 of "perf test" now complete successfully.
Signed-off-by: NSteven Walter <stevenrwalter@gmail.com>
Signed-off-by: NWade Farnsworth <wade_farnsworth@mentor.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Supplying the asm-generic/syscall.h interface is a
pre-requisite for HAVE_ARCH_TRACEHOOK
Signed-off-by: NSteven Walter <stevenrwalter@gmail.com>
Signed-off-by: NWade Farnsworth <wade_farnsworth@mentor.com>
Reviewed-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>