Let perf find libtraceevent headers when detecting libtracefs

--- a/tools/build/feature/test-libtracefs.c
+++ b/tools/build/feature/test-libtracefs.c
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
-#include <tracefs/tracefs.h>
+#include <tracefs.h>
 
 int main(void)
 {
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -185,6 +185,9 @@ endif
 FEATURE_CHECK_CFLAGS-libbabeltrace := $(LIBBABELTRACE_CFLAGS)
 FEATURE_CHECK_LDFLAGS-libbabeltrace := $(LIBBABELTRACE_LDFLAGS) -lbabeltrace-ctf
 
+FEATURE_CHECK_CFLAGS-libtracefs := $(shell $(PKG_CONFIG) --cflags libtracefs)
+FEATURE_CHECK_LDFLAGS-libtracefs := $(shell $(PKG_CONFIG) --libs libtracefs)
+
 ifdef LIBZSTD_DIR
   LIBZSTD_CFLAGS  := -I$(LIBZSTD_DIR)/lib
   LIBZSTD_LDFLAGS := -L$(LIBZSTD_DIR)/lib