Revert "Use host_linux instead of linux_glibc to support musl as well"

This reverts commit 961538b44a37648388f3a7474a18ad4f30219345.

Reason for revert: breaks musl build, musl already has the bionic copy of the linux headers and doesn't need the linux-private directory.

Change-Id: I9e435032d45c0769dbdbc82f64edc3dbd662bc42
diff --git a/Android.bp b/Android.bp
index d089f88..9f8e3ee 100644
--- a/Android.bp
+++ b/Android.bp
@@ -45,7 +45,7 @@
         darwin: {
             enabled: false,
         },
-        host_linux: {
+        linux_glibc: {
             local_include_dirs: [
                 "include/linux-private",
             ],