Rename SPL_MUSB_NEW_SUPPORT to SPL_MUSB_NEW

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/spl/Kconfig b/common/spl/Kconfig
index 6d44265..016eeac 100644
--- a/common/spl/Kconfig
+++ b/common/spl/Kconfig
@@ -761,7 +761,7 @@
 	  devices. See SPL_NAND_SUPPORT and SPL_ONENAND_SUPPORT for how
 	  to enable specific MTD drivers.
 
-config SPL_MUSB_NEW_SUPPORT
+config SPL_MUSB_NEW
 	bool "Support new Mentor Graphics USB"
 	help
 	  Enable support for Mentor Graphics USB in SPL. This is a new