perf/x86: Move perf_event.h to its new home

Now that all functionality has been moved to arch/x86/events/, move the
perf_event.h header and adjust include paths.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1455098123-11740-18-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c
index a8abd08..51087c2 100644
--- a/arch/x86/events/amd/ibs.c
+++ b/arch/x86/events/amd/ibs.c
@@ -14,7 +14,7 @@
 
 #include <asm/apic.h>
 
-#include "../../kernel/cpu/perf_event.h"
+#include "../perf_event.h"
 
 static u32 ibs_caps;