libwatchdog: Add host support

Test: Build libwatchdog
Bug: 151789676

Change-Id: I6161e5ddb4e3883dfeda01828b768082610a5b57
diff --git a/media/libwatchdog/Android.bp b/media/libwatchdog/Android.bp
index 1a87824..f7f0db7 100644
--- a/media/libwatchdog/Android.bp
+++ b/media/libwatchdog/Android.bp
@@ -14,6 +14,7 @@
 
 cc_library {
     name: "libwatchdog",
+    host_supported: true,
     srcs: [
         "Watchdog.cpp",
     ],
@@ -29,6 +30,11 @@
         darwin: {
             enabled: false,
         },
+        linux_glibc: {
+            cflags: [
+                "-Dsigev_notify_thread_id=_sigev_un._tid",
+            ],
+        },
     },
     apex_available: ["com.android.media"],
     min_sdk_version: "29",