bionic: Remove libc/Android.mk file

Since there are no longer any Android.mk files in subdirs, the
top-level one can go.

Test: m
Change-Id: Ifc51545fc82a5eaa0801babd3ede20d911f1b9c3
diff --git a/libc/Android.mk b/libc/Android.mk
deleted file mode 100644
index 888404c..0000000
--- a/libc/Android.mk
+++ /dev/null
@@ -1,4 +0,0 @@
-LOCAL_PATH := $(call my-dir)
-
-include $(call all-makefiles-under,$(LOCAL_PATH))
-