ftrace: fix depends

A lot of tracers have HAVE_FTRACE as a dependent config where it
really should not. The HAVE_FTRACE is a misnomer (soon to be fixed)
and describes if the architecture has the function tracer (mcount)
implemented. The ftrace infrastructure is implemented in all archs.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>