TDLS: Provide external control to specify the peers for setup

TDLS: Provide external control to specify the peers for setup

There are use cases requesting the host driver to initiate the TDLS
setup with the peer only when configured by the external applications.
Thus, enable this control by tdls_external_control=1 and pass the
requisite information for the specific TDLS operation to the driver
on the request from such use cases.

This operation mode expects the driver to initiate TDLS link
automatically based on signal strength and traffic to a peer and tear
down links whenever they are not used or suitable due to signal strength
etc. The list of peers with which such operations are to be performed
are provided with the TDLS driver operations.

Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>