ath10k: htc: move htc ctrl ep connect to htc_init

This patch moves the HTC ctrl service connect from
htc_wait_target to htc_init.

This is done in order to make sure the htc ctrl service
is setup properly before hif_start is called.

The reason for this is that we want the HTC ctrl service
callback to be initialized before the target sends the
HTC ready message.

The ready message will always be transmitted on endpoint 0
(which is always assigned to the HTC control service) so it
makes more sense if HTC control has been connected before the
ready message is received.

Since the service to pipe mapping is done as a part of
the service connect, the get_default_pipe call is redundant
and was removed.

Signed-off-by: Erik Stromdahl <erik.stromdahl@gmail.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>