Bluetooth: Move LE event mask setting into init3 phase

During init2 phase, the LE local features have not be read yet so
we aren't able to rely on hdev->le_features to determine if the
controller supports the Connection Parameters Request Procedure.

For that reason, this patch moves LE event mask setting from init2
into init3 initialization phase.

The hdev->le_features mask will be checked by the next patch in order
to know if "LE Remote Connection Parameter Request Event" should be
enabled.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>