Add asm/a.out.h to arm64/mips/mips64

The common header include/linux/a.out.h include asm/a.out.h, but
arm64/mips/mips64 don't have it.  Add a placeholder before bionic
has it

Change-Id: I7084e0beabe86fec32987a89e66d6c094f1e8c22
diff --git a/ndk/platforms/android-21/arch-arm64/include/asm/a.out.h b/ndk/platforms/android-21/arch-arm64/include/asm/a.out.h
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/ndk/platforms/android-21/arch-arm64/include/asm/a.out.h
@@ -0,0 +1 @@
+
diff --git a/ndk/platforms/android-21/arch-mips/include/asm/a.out.h b/ndk/platforms/android-21/arch-mips/include/asm/a.out.h
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/ndk/platforms/android-21/arch-mips/include/asm/a.out.h
@@ -0,0 +1 @@
+
diff --git a/ndk/platforms/android-21/arch-mips64/include/asm/a.out.h b/ndk/platforms/android-21/arch-mips64/include/asm/a.out.h
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/ndk/platforms/android-21/arch-mips64/include/asm/a.out.h
@@ -0,0 +1 @@
+