tracing: Move trace sysctls into trace.c

tracing: Move trace sysctls into trace.c

Move trace ctl tables into their own const array in
kernel/trace/trace.c. The sysctl table register is called with
subsys_initcall placing if after its original place in proc_root_init.
This is part of a greater effort to move ctl tables into their
respective subsystems which will reduce the merge conflicts in
kernel/sysctl.c.

Signed-off-by: Joel Granados <joel.granados@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>