board: phytec: phycore-imx93: Enter fastboot on USB boot by default

In case board is booted from USB, enter fastboot by default to enable
the UUU flashing. In case of abort continue with the regular bootstd
scan. User also has possibility to override the default bootcmd from
the environment. Last but not least, this syncs behavior with other
PHYTEC boards from the i.MX family.

Signed-off-by: Primoz Fiser <primoz.fiser@norik.com>
Reviewed-by: Benjamin Hahn <B.Hahn@phytec.de>

board/phytec/phycore_imx93/phycore-imx93.c

@@ -41,6 +41,11 @@ int board_late_init(void)
 	case MMC1_BOOT:
 		env_set_ulong("mmcdev", 0);
 		break;
+	case USB_BOOT:
+		printf("Detect USB boot. Will enter fastboot mode!\n");
+		if (!strcmp(env_get("bootcmd"), env_get_default("bootcmd")))
+			env_set("bootcmd", "fastboot 0; bootflow scan -lb;");
+		break;
 	default:
 		break;
 	}