ath10k: add the PCI PM core suspend/resume ops

The actual PCI suspend/resume in ath10k has been handled in wow.c,
but in the case of the device doesn't support remote wakeup,
the .hif_suspend() and .hif_resume() will never be handled.

  ath10k_wow_op_suspend()
  {
	if (WARN_ON(!test_bit(ATH10K_FW_FEATURE_WOWLAN_SUPPORT,
		    ar->running_fw->fw_file.fw_features))) {
		ret = 1;
		goto exit;
	}

	....

	ret = ath10k_hif_suspend(ar);
  }

So register the PCI PM core to support the suspend/resume if the device
doesn't support remote wakeup.

Signed-off-by: Ryan Hsu <ryanhsu@qti.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>