Fixed cross key for LE when paired over BR-EDR

SMP state machine was resending security request and waiting for a response
when paired over BR-EDR. The state machine state timed out due to this and
SMP failed while doing cross key pairing. Thus, user was asked for pairing
again.

Original author: Priti Aghera <paghera@broadcom.com>
Change-Id: I568f936bb7bee21fb78e8454469ecad3445f026f