perf/uapi: Clean up <uapi/linux/perf_event.h> a bit

When applying a recent commit to the <uapi/linux/perf_event.h>
header I noticed that we have accumulated quite a bit of
historic noise in this header, so do a bit of spring cleaning:

 - Define bitfields in a vertically aligned fashion, like
   perf_event_mmap_page::capabilities already does. This
   makes it easier to see the distribution and sizing of
   bits within a word, at a glance. The following is much
   more readable:

			__u64	cap_bit0		: 1,
				cap_bit0_is_deprecated	: 1,
				cap_user_rdpmc		: 1,
				cap_user_time		: 1,
				cap_user_time_zero	: 1,
				cap_user_time_short	: 1,
				cap_____res		: 58;

   Than:

			__u64	cap_bit0:1,
				cap_bit0_is_deprecated:1,
				cap_user_rdpmc:1,
				cap_user_time:1,
				cap_user_time_zero:1,
				cap_user_time_short:1,
				cap_____res:58;

   So convert all bitfield definitions from the latter style to the
   former style.

 - Fix typos and grammar

 - Fix capitalization

 - Remove whitespace noise

 - Harmonize the definitions of various generations and groups of
   PERF_MEM_ ABI values.

 - Vertically align all definitions and assignments to the same
   column (48), as the first definition (enum perf_type_id),
   throughout the entire header.

 - And in general make the code and comments to be more in sync
   with each other and to be more readable overall.

No change in functionality.

Copy the changes over to tools/include/uapi/linux/perf_event.h.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250521221529.2547099-1-irogers@google.com

Author: Ingo Molnar