ath11k: fix pdev when invoking ath11k_wmi_send_twt_enable_cmd()

The code currently uses the wrong pdev id when enabling TWT. Fix this by
using the correct ones.

Fixes: e65a616f4e74 ("ath11k: add TWT support")
Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: Pradeep Kumar Chitrapu <pradeepc@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>