libperf: Move perf_event_attr field from perf's evsel to libperf's perf_evsel

libperf: Move perf_event_attr field from perf's evsel to libperf's perf_evsel

Move the perf_event_attr struct fron 'struct evsel' to 'struct perf_evsel'.

Committer notes:

Fixed up these:

 tools/perf/arch/arm/util/auxtrace.c
 tools/perf/arch/arm/util/cs-etm.c
 tools/perf/arch/arm64/util/arm-spe.c
 tools/perf/arch/s390/util/auxtrace.c
 tools/perf/util/cs-etm.c

Also

  cc1: warnings being treated as errors
  tests/sample-parsing.c: In function 'do_test':
  tests/sample-parsing.c:162: error: missing initializer
  tests/sample-parsing.c:162: error: (near initialization for 'evsel.core.cpus')

   	struct evsel evsel = {
   		.needs_swap = false,
  -		.core.attr = {
  -			.sample_type = sample_type,
  -			.read_format = read_format,
  +		.core = {
  +			. attr = {
  +				.sample_type = sample_type,
  +				.read_format = read_format,
  +			},

  [perfbuilder@a70e4eeb5549 /]$ gcc --version |& head -1
  gcc (GCC) 4.4.7

Also we don't need to include perf_event.h in
tools/perf/lib/include/perf/evsel.h, forward declaring 'struct
perf_event_attr' is enough. And this even fixes the build in some
systems where things are used somewhere down the include path from
perf_event.h without defining __always_inline.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190721112506.12306-43-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>