perf event: Drop perf_regs.h include, not needed anymore

Bugzilla: https://bugzilla.redhat.com/2177180

upstream
========
commit b15cf900d11d4db2c2dac544a27f3e1217bdd0d4
Author: Arnaldo Carvalho de Melo <acme@redhat.com>
Date: Tue Oct 25 17:34:44 2022 -0300

description
===========
Since commit c897899752478d4c ("perf tools: Prevent out-of-bounds access
to registers") the util/event.h header doesn't use anything from
util/perf_regs.h, so drop it to untangle the header dependency tree a
bit, speeding up compilation.

    Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Signed-off-by: Michael Petlan <mpetlan@redhat.com>

tools/perf/util/event.h

@@ -12,8 +12,6 @@
 #include <perf/event.h>
 #include <linux/types.h>
 
-#include "perf_regs.h"
-
 struct dso;
 struct machine;
 struct perf_event_attr;