Remove libportable from core_base.mk.

Change-Id: I3fae0625c68db885bd2fba502d31fe3c524d4f47
diff --git a/target/product/core_base.mk b/target/product/core_base.mk
index 69bde63..8161434 100644
--- a/target/product/core_base.mk
+++ b/target/product/core_base.mk
@@ -36,7 +36,6 @@
     libkeystore \
     libmdnssd \
     libnfc_ndef \
-    libportable \
     libpowermanager \
     libspeexresampler \
     libstagefright_chromium_http \