Bluetooth: Use AUTO_OFF constant in jiffies

Move AUTO_OFF_TIMEOUT to other constants changing name to
HCI_AUTO_OFF_TIMEOUT and convert to jiffies.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>