perf tools: Remove needless libtraceevent include directives

Remove traceevent/event-parse.h and traceevent/trace-seq.h from places
where it is not needed.

Should avoid rebuilding those files when these traceevent headers get
changed.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Link: https://lkml.kernel.org/n/tip-26hn75jn9rdealn4uqtzend6@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>