Unpair the other transport on a device paired

When unpair is initiated for LE or BR-EDR transport for a device,
close the link for other transport and unpair the device on
both transports, since both transports on a device are paired
due to cross key.

Original author: Priti Aghera <paghera@broadcom.com>
Change-Id: I13d4757eb056c4bd4c7cc0699ec61a28852702c5