ti: j721e_evm: Add USB to the default boot order

This family of platforms typically has a USB port, and so attempting to
boot from it, and making it first, will provide a better overall user
experience.

Signed-off-by: Tom Rini <trini@konsulko.com>

include/configs/j721e_evm.h

@@ -161,7 +161,14 @@
 # define BOOT_TARGET_DHCP(func)
 #endif
 
+#ifdef CONFIG_CMD_USB
+# define BOOT_TARGET_USB(func)	func(USB, usb, 0)
+#else
+# define BOOT_TARGET_USB(func)
+#endif
+
 #define BOOT_TARGET_DEVICES(func) \
+	BOOT_TARGET_USB(func) \
 	func(MMC, mmc, 1) \
 	func(MMC, mmc, 0) \
 	BOOT_TARGET_PXE(func) \