Bluetooth: Remove unused mask parameter in sco_conn_defer_accept

From Bluetooth Core v4.0 specification, 7.1.8 Accept Connection Request
Command "When accepting synchronous connection request, the Role
parameter is not used and will be ignored by the BR/EDR Controller."

Signed-off-by: Frédéric Dalleau <frederic.dalleau@linux.intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>