FROMGIT: Bluetooth: btintel_pcie: Support for S4 (Hibernate)

During S4 (hibernate), the Bluetooth device loses power. Upon resume,
the driver performs the following actions:

1. Unregisters hdev
2. Calls function level reset
3. Registers hdev

Test case:
- run command sudo rtcwake -m disk -s 60

BUG=b:400831265
TEST=Build and test bluetooth on PTLRVP

(cherry picked from commit d6ac812251e5e52aedb30bd67a2d53e017af3098
https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.git

 master)

Change-Id: I295979d9848e88f5e65a4b323e9d8f93cbf32c9e
Signed-off-by: Ravindra <ravindra@intel.com>
Signed-off-by: Kiran K <kiran.k@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>