perf hashmap: Tidy hashmap dependency

perf hashmap: Tidy hashmap dependency

When libbpf is present the build uses definitions in libbpf hashmap.c,
however, libbpf's hashmap.h wasn't being used. Switch to using the
correct hashmap.h dependent on the define HAVE_LIBBPF_SUPPORT. This was
the original intent in:

  https://lore.kernel.org/lkml/20200515221732.44078-8-irogers@google.com/

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20220824050604.352156-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>