Remove libkeymaster_staging

Test: Builds
Change-Id: I62cc11ec4aca5ccbe2d7d56e9ddf0c78591383f7
diff --git a/trusty/keymaster/Android.bp b/trusty/keymaster/Android.bp
index 322a63d..479a7e0 100644
--- a/trusty/keymaster/Android.bp
+++ b/trusty/keymaster/Android.bp
@@ -36,7 +36,6 @@
         "libcrypto",
         "libcutils",
         "libkeymaster_portable",
-        "libkeymaster_staging",
         "libtrusty",
         "libkeymaster_messages",
         "libsoftkeymasterdevice",