xtensa: update arch features

xtensa now supports tracehook, queued spinlocks and rwlocks. Update
corresponding Documentation/features entries.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Documentation/features/core/tracehook/arch-support.txt

@@ -30,5 +30,5 @@
     |          um: | TODO |
     |   unicore32: | TODO |
     |         x86: |  ok  |
-    |      xtensa: | TODO |
+    |      xtensa: |  ok  |
     -----------------------