vibrator: Drop kernel header dependency

* This is a partial revert of 5fba81168e8446448da68a5e546c2aa77b8dd148.
* CAF adds the kernel headers dep to fetch one single value that is
  removed in that commit. Easier to just carry it here, especially
  considering most devices won't have this in generated_kernel_headers,
  even.

Change-Id: I5b7daab2731e4b6b529cdb1ccf0fe173f677f8fd

aidl/vibrator/Android.bp

@@ -59,7 +59,6 @@ cc_library_shared {
         "android.hardware.vibrator-V1-ndk_platform",
     ],
     export_include_dirs: ["include"],
-    header_libs: ["qti_kernel_headers"],
 }
 
 cc_binary {