perf docs: Update the documentation for the save_type filter

Update the documentation to reflect the kernel changes.
Signed-off-by: NKan Liang <kan.liang@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20220816125612.2042397-2-kan.liang@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf-record.txt

@@ -397,6 +397,9 @@ following filters are defined:
 	- abort_tx: only when the target is a hardware transaction abort
 	- cond: conditional branches
 	- save_type: save branch type during sampling in case binary is not available later
+		     For the platforms with Intel Arch LBR support (12th-Gen+ client or
+		     4th-Gen Xeon+ server), the save branch type is unconditionally enabled
+		     when the taken branch stack sampling is enabled.
 
 +
 The option requires at least one branch type among any, any_call, any_ret, ind_call, cond.