perf: Remove include of cgroup.h from perf_event.h

Move struct perf_cgroup_info and perf_cgroup to
kernel/perf/core.c, and then we can remove include of cgroup.h.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/513568A0.6020804@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index e47ee46..8737e1c 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -21,7 +21,6 @@
  */
 
 #ifdef CONFIG_PERF_EVENTS
-# include <linux/cgroup.h>
 # include <asm/perf_event.h>
 # include <asm/local64.h>
 #endif
@@ -299,22 +298,7 @@
 #define PERF_ATTACH_GROUP	0x02
 #define PERF_ATTACH_TASK	0x04
 
-#ifdef CONFIG_CGROUP_PERF
-/*
- * perf_cgroup_info keeps track of time_enabled for a cgroup.
- * This is a per-cpu dynamically allocated data structure.
- */
-struct perf_cgroup_info {
-	u64				time;
-	u64				timestamp;
-};
-
-struct perf_cgroup {
-	struct				cgroup_subsys_state css;
-	struct				perf_cgroup_info *info;	/* timing info, one per cpu */
-};
-#endif
-
+struct perf_cgroup;
 struct ring_buffer;
 
 /**