Revert portions of "ANDROID: vendor_hooks: Add hooks for scheduler"

This reverts part of commit 53e80997.

The hook android_rvh_check_preempt_wakeup_ignore 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: 182441701
Cc: xieliujie <xieliujie@oppo.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I69bdc14143760bfdd07bbd72ed3d5a4127fbc4c8