Rename SPL_USB_HOST_SUPPORT to SPL_USB_HOST

Rename this option so that CONFIG_IS_ENABLED can be used with it.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/common/Makefile b/common/Makefile
index 829ea5f..9063ed9 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -72,7 +72,7 @@
 obj-$(CONFIG_SPL_NET_SUPPORT) += miiphyutil.o
 obj-$(CONFIG_$(SPL_TPL_)OF_LIBFDT) += fdt_support.o
 
-ifdef CONFIG_SPL_USB_HOST_SUPPORT
+ifdef CONFIG_SPL_USB_HOST
 obj-y += usb.o
 obj-y += usb_hub.o
 obj-$(CONFIG_SPL_USB_STORAGE) += usb_storage.o