BUILD.gn: add missing dependency onto marl for SubzeroReactor

To fix broken Chromium build:
https://chromium-review.googlesource.com/c/chromium/src/+/2102747

Bug: fix Chromium build
Change-Id: I00e3bbe3087d6c885164d6b91e55ac50a89b5dad
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/42348
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Tested-by: Antonio Maiorano <amaiorano@google.com>
diff --git a/src/Reactor/BUILD.gn b/src/Reactor/BUILD.gn
index 66b4bf1..1154dba 100644
--- a/src/Reactor/BUILD.gn
+++ b/src/Reactor/BUILD.gn
@@ -303,6 +303,7 @@
   }
   swiftshader_source_set("swiftshader_subzero_reactor") {
     deps = [
+      "../../third_party/marl:Marl",
       ":swiftshader_reactor_base",
       ":swiftshader_subzero",
     ]