Bluetooth: Fix clearing of debug and linkkey flags

This patch fixes clearing of HCI_LINK_KEYS and HCI_DEBUG_KEYS
dev_flags while resetting. Without this patch pairing does
not work over management interface for BR-EDR devices.

Signed-off-by: Hemant Gupta <hemant.gupta@stericsson.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>