perf hist: Remove symbol.h from hist.h, just fwd decls are needed

To reduce the includes dependencies.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-cmvg5ght75mmfg1efeyna9rn@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/callchain.c

@@ -26,6 +26,7 @@
 #include "map.h"
 #include "callchain.h"
 #include "branch.h"
+#include "symbol.h"
 
 #define CALLCHAIN_PARAM_DEFAULT			\
 	.mode		= CHAIN_GRAPH_ABS,	\