usb: gadget: udc: atmel: convert to platform driver

The driver won't probe on a LAN9668 because the pinctrl driver isn't
ready yet. Probe deferral is not supported because the init section
is already discarded. With fw_devlink enabled, the probe won't even
be called. Convert the driver to a proper platform driver.
Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20220705131951.1388968-2-michael@walle.ccSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/udc/atmel_usba_udc.c

@@ -2060,7 +2060,7 @@ static const struct usba_udc_errata at91sam9g45_errata = {
 	.pulse_bias = at91sam9g45_pulse_bias,
 };
 
-static const struct usba_ep_config ep_config_sam9[] __initconst = {
+static const struct usba_ep_config ep_config_sam9[] = {
 	{ .nr_banks = 1 },				/* ep 0 */
 	{ .nr_banks = 2, .can_dma = 1, .can_isoc = 1 },	/* ep 1 */
 	{ .nr_banks = 2, .can_dma = 1, .can_isoc = 1 },	/* ep 2 */
@@ -2070,7 +2070,7 @@ static const struct usba_ep_config ep_config_sam9[] __initconst = {
 	{ .nr_banks = 3, .can_dma = 1, .can_isoc = 1 },	/* ep 6 */
 };
 
-static const struct usba_ep_config ep_config_sama5[] __initconst = {
+static const struct usba_ep_config ep_config_sama5[] = {
 	{ .nr_banks = 1 },				/* ep 0 */
 	{ .nr_banks = 3, .can_dma = 1, .can_isoc = 1 },	/* ep 1 */
 	{ .nr_banks = 3, .can_dma = 1, .can_isoc = 1 },	/* ep 2 */
@@ -2449,6 +2449,7 @@ static int usba_udc_resume(struct device *dev)
 static SIMPLE_DEV_PM_OPS(usba_udc_pm_ops, usba_udc_suspend, usba_udc_resume);
 
 static struct platform_driver udc_driver = {
+	.probe		= usba_udc_probe,
 	.remove		= usba_udc_remove,
 	.driver		= {
 		.name		= "atmel_usba_udc",
@@ -2456,8 +2457,7 @@ static struct platform_driver udc_driver = {
 		.of_match_table	= atmel_udc_dt_ids,
 	},
 };
-
-module_platform_driver_probe(udc_driver, usba_udc_probe);
+module_platform_driver(udc_driver);
 
 MODULE_DESCRIPTION("Atmel USBA UDC driver");
 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");