Bluetooth: Convert MSFT filter HCI cmd to hci_sync

The msft_set_filter_enable() command was using the deprecated
hci_request mechanism rather than hci_sync. This caused the warning error:
hci0: HCI_REQ-0xfcf0

Signed-off-by: Brian Gix <brian.gix@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>