Include what you use

This doesn't need utils/Log.h, just log/log.h and some stdlib headers.

Bug: 33241851
Test: m -j libhardware
Change-Id: Id73059f5636af42b0d1680b89f6ca27f466d9ea8
diff --git a/Android.bp b/Android.bp
index 64f5c8e..2c46ce9 100644
--- a/Android.bp
+++ b/Android.bp
@@ -14,6 +14,7 @@
         "liblog",
         "libdl",
     ],
+    header_libs: ["libsystem_headers"],
     cflags: ["-DQEMU_HARDWARE"],
     export_include_dirs: ["include"],
 }