Revert "perf tools: event.h needs asm/perf_regs.h"

This reverts commit e083a21fcac9311ca425e600a15332f4792c56cc.

Not needed at all, tools/perf/util/perf_regs.h, included via:

#include "perf_regs.h"

Should have a definition for PERF_REGS_MAX, and since this is dependent
on HAVE_PERF_REGS_SUPPORT, fixes the build on powerpc, noticed by trying
to cross compile this from ubuntu16.04 with a locally build libz &
elfutils pair, since those are not available in multilib packages.

Cc: Jiri Olsa <[e-mail]>
Cc: Naveen N. Rao <[e-mail]>
Cc: Stephane Eranian <[e-mail]>
Cc: Sukadev Bhattiprolu <[e-mail]>
Link: http://lkml.kernel.org/n/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/util/event.h

···
 #include "map.h"
 #include "build-id.h"
 #include "perf_regs.h"
-#include <asm/perf_regs.h>
 
 struct mmap_event {
 	struct perf_event_header header;