FROMLIST: bus: mhi: host: pci_generic: Switch to async power up to avoid boot delays

Some modem devices can take significant time (up to 20 secs for sdx75) to
enter mission mode during initialization. Currently, mhi_sync_power_up()
waits for this entire process to complete, blocking other driver probes
and delaying system boot.

Switch to mhi_async_power_up() so probe can return immediately while MHI
initialization continues in the background. This eliminates lengthy boot
delays and allows other drivers to probe in parallel, improving overall
system boot performance.

Link: https://lore.kernel.org/all/20260303-b4-async_power_on-v2-1-d3db81eb457d@oss.qualcomm.com/
Fixes: 5571519 ("bus: mhi: host: pci_generic: Add SDX75 based modem support")
Cc: stable@vger.kernel.org
Signed-off-by: Qiang Yu <qiang.yu@oss.qualcomm.com>

Author: qianyu-qcom

drivers/bus/mhi/host/pci_generic.c

@@ -1392,7 +1392,7 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 		goto err_unregister;
 	}
 
-	err = mhi_sync_power_up(mhi_cntrl);
+	err = mhi_async_power_up(mhi_cntrl);
 	if (err) {
 		dev_err(&pdev->dev, "failed to power up MHI controller\n");
 		goto err_unprepare;