Correct SPL uses of CMD_USB

This converts 8 usages of this option to the non-SPL form, since there is
no SPL_CMD_USB defined in Kconfig

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/configs/rpi.h b/include/configs/rpi.h
index 7c306cb..4da982f 100644
--- a/include/configs/rpi.h
+++ b/include/configs/rpi.h
@@ -131,7 +131,7 @@
 	#define BOOT_TARGET_MMC(func)
 #endif
 
-#if CONFIG_IS_ENABLED(CMD_USB)
+#if IS_ENABLED(CONFIG_CMD_USB)
 	#define BOOT_TARGET_USB(func) func(USB, usb, 0)
 #else
 	#define BOOT_TARGET_USB(func)