libdl: Rename LIBC_PRIVATE to LIBC_PLATFORM

Bug: http://b/26386014
Change-Id: I3255faac66a96867aed302e205e3644b40ce7750
(cherry picked from commit 98cdef39dccad972a527b274be08a1905047a39a)
diff --git a/libdl/libdl.arm64.map b/libdl/libdl.arm64.map
index b3de6bf..0a5ac97 100644
--- a/libdl/libdl.arm64.map
+++ b/libdl/libdl.arm64.map
@@ -23,12 +23,8 @@
 LIBC_PLATFORM {
   global:
     android_dlwarning;
-} LIBC_N;
-
-LIBC_PRIVATE {
-  global:
     android_get_application_target_sdk_version;
     android_set_application_target_sdk_version;
     android_get_LD_LIBRARY_PATH;
     android_update_LD_LIBRARY_PATH;
-} LIBC_PLATFORM;
+} LIBC_N;