pan/bi: Annotate stop bit (canonically "Z-bit")

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6793>
diff --git a/src/panfrost/bifrost/disassemble.c b/src/panfrost/bifrost/disassemble.c
index 5691af5..9894363 100644
--- a/src/panfrost/bifrost/disassemble.c
+++ b/src/panfrost/bifrost/disassemble.c
@@ -446,6 +446,7 @@
                 uint64_t const0 = bits(words[0], 8, 32) << 4 | (uint64_t) words[1] << 28 | bits(words[2], 0, 4) << 60;
                 uint64_t const1 = bits(words[2], 4, 32) << 4 | (uint64_t) words[3] << 32;
 
+                /* Z-bit */
                 bool stop = tag & 0x40;
 
                 if (verbose) {