perf copyfile: Move copyfile routines to separate files

Further reducing the util.c hodgepodge files.

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-0i62zh7ok25znibyebgq0qs4@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/Build

@@ -3,6 +3,7 @@ perf-y += block-range.o
 perf-y += build-id.o
 perf-y += cacheline.o
 perf-y += config.o
+perf-y += copyfile.o
 perf-y += ctype.o
 perf-y += db-export.o
 perf-y += env.o