Add pthread_sigqueue.c to sources.bp am: 7e8fb9d58a

Original change: https://android-review.googlesource.com/c/platform/external/musl/+/1969743

Change-Id: I88e22ed6470e951362893e40d58990374292a048
diff --git a/sources.bp b/sources.bp
index bb55ddb..dedf466 100644
--- a/sources.bp
+++ b/sources.bp
@@ -1116,6 +1116,7 @@
         "src/thread/pthread_setschedprio.c",
         "src/thread/pthread_setspecific.c",
         "src/thread/pthread_sigmask.c",
+        "src/thread/pthread_sigqueue.c",
         "src/thread/pthread_spin_destroy.c",
         "src/thread/pthread_spin_init.c",
         "src/thread/pthread_spin_lock.c",