panvk: fix broken clock sync after using CLOCK_MONOTONIC_RAW

Use sequence-scoped clock (64 <= ID < 128) for GPU clock because there's
no central daemon emitting consistent snapshots for synchronization
between CPU and GPU clocks on behalf of renderstages and counters
producers.

When CPU clock is the same with the authoritative trace clock (normally
default to CLOCK_BOOTTIME), perfetto drops the non-monotonic snapshots
to ensure validity of the global source clock in the resolution graph.
When they are different, the clocks are marked invalid and the rest of
the clock syncs will fail during trace processing.

Now that PanVK has switched to use CLOCK_MONOTONIC_RAW CPU clock, here
we make the GPU clock sequence-scoped so that clock sync for all the
trace packets emitted with the same trusted_packet_sequence_id will be
done in an isolated manner (basically perfetto makes each scoped GPU
clock globally unique).

Meanwhile, since the clock is now sequence-scoped (unique per producer +
writer pair within the tracing session), we can simply pick 64 to start
with, and later extend to support multi-gpu (offset with primary minor).

Fixes: e278a89fdd ("panvk/perfetto: improve clock synchronization using CLOCK_MONOTONIC_RAW")
Reviewed-by: Mary Guillemard <mary.guillemard@collabora.com>
Reviewed-by: Chia-I Wu <olvaffe@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/37355>

src/panfrost/vulkan/panvk_utrace_perfetto.cc

@@ -288,8 +288,30 @@ PANVK_UTRACE_PERFETTO_PROCESS_EVENT(sync64_wait, SYNC_WAIT)
 static uint32_t
 get_gpu_clock_id(void)
 {
-   /* see https://perfetto.dev/docs/concepts/clock-sync */
-   return _mesa_hash_string("org.freedesktop.mesa.panfrost") | 0x80000000;
+   /* see https://perfetto.dev/docs/concepts/clock-sync
+    *
+    * Use sequence-scoped clock (64 <= ID < 128) for GPU clock because there's
+    * no central daemon emitting consistent snapshots for synchronization
+    * between CPU and GPU clocks on behalf of renderstages and counters
+    * producers.
+    *
+    * When CPU clock is the same with the authoritative trace clock (normally
+    * default to CLOCK_BOOTTIME), perfetto drops the non-monotonic snapshots
+    * to ensure validity of the global source clock in the resolution graph.
+    * When they are different, the clocks are marked invalid and the rest of
+    * the clock syncs will fail during trace processing.
+    *
+    * Now that PanVK has switched to use CLOCK_MONOTONIC_RAW CPU clock, here
+    * we make the GPU clock sequence-scoped so that clock sync for all the
+    * trace packets emitted with the same trusted_packet_sequence_id will be
+    * done in an isolated manner (basically perfetto makes each scoped GPU
+    * clock globally unique).
+    *
+    * Meanwhile, since the clock is now sequence-scoped (unique per producer +
+    * writer pair within the tracing session), we can simply pick 64 to start
+    * with since there's no multi-mali-gpu setup yet.
+    */
+   return 64;
 }
 
 static void