perf arm-spe: Fix a dangling Documentation/arm64 reference

The arm64 documentation has moved under Documentation/arch/.  Fix up a
dangling reference to match.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

tools/perf/util/arm-spe-decoder/arm-spe-decoder.c

@@ -51,7 +51,7 @@ static u64 arm_spe_calc_ip(int index, u64 payload)
 		 * (bits [63:56]) is assigned as top-byte tag; so we only can
 		 * retrieve address value from bits [55:0].
 		 *
-		 * According to Documentation/arm64/memory.rst, if detects the
+		 * According to Documentation/arch/arm64/memory.rst, if detects the
 		 * specific pattern in bits [55:52] of payload which falls in
 		 * the kernel space, should fixup the top byte and this allows
 		 * perf tool to parse DSO symbol for data address correctly.