spi: Use PM ops instead of legacy suspend/resume

New drivers should use PM ops instead of the legacy suspend/resume
callbacks. Update the SPI device driver guide to reflect this.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/spi/spi-summary

@@ -342,12 +342,11 @@ SPI protocol drivers somewhat resemble platform device drivers:
 		.driver = {
 			.name		= "CHIP",
 			.owner		= THIS_MODULE,
+			.pm		= &CHIP_pm_ops,
 		},
 
 		.probe		= CHIP_probe,
 		.remove		= CHIP_remove,
-		.suspend	= CHIP_suspend,
-		.resume		= CHIP_resume,
 	};
 
 The driver core will automatically attempt to bind this driver to any SPI