Revert "ANDROID: workqueue: add vendor hook for wq lockup information"

This reverts commit 34f08745.

The hook android_vh_wq_lockup_pool is not used by any vendor, so remove
it to help with merge issues with future LTS releases.

If this is needed by any real user, it can easily be reverted to add it
back and then the symbol should be added to the abi list at the same
time to prevent it from being removed again later.

Bug: 203756332
Bug: 169374262
Cc: Sangmoon Kim <sangmoon.kim@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I84eb7e1abc535a4efecd2b6071ef6d25fa2c1e2e