patches: remove usage of wait_on_bit_timeout() on older kernels

This was intoduced in this commit:
commit 431a9e1713c512bb96d570dc84e518384d1ac62b
Author: Loic Poulain <loic.poulain@intel.com>
Date:   Wed Jul 1 12:20:26 2015 +0200

    Bluetooth: hci_uart: Add basic support for Intel Lightning Peak devices

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>