Fix mac build

-lrt doesn't exist on the mac

Change-Id: I5f9c62bc2338a09141d2e1baa29ff6a68eb2c6b2
diff --git a/build/Android.bp b/build/Android.bp
index ec374f2..630cf3c 100644
--- a/build/Android.bp
+++ b/build/Android.bp
@@ -101,6 +101,9 @@
                 // Apple, it's a pain.
                 "-Wmissing-noreturn",
             ],
+            host_ldlibs: [
+                "-lrt",
+            ],
         },
         host: {
             cflags: [
@@ -111,7 +114,6 @@
             host_ldlibs: [
                 "-ldl",
                 "-lpthread",
-                "-lrt",
             ],
         },
     },