Convert CONFIG_CMD_FUSE to Kconfig

This converts the following to Kconfig:
   CONFIG_CMD_FUSE

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/cpu/armv7/mx6/Kconfig b/arch/arm/cpu/armv7/mx6/Kconfig
index 0ff9045..4fd60d4 100644
--- a/arch/arm/cpu/armv7/mx6/Kconfig
+++ b/arch/arm/cpu/armv7/mx6/Kconfig
@@ -7,6 +7,7 @@
 	select ARM_ERRATA_751472 if !MX6UL
 	select ARM_ERRATA_761320 if !MX6UL
 	select ARM_ERRATA_794072 if !MX6UL
+	imply CMD_FUSE
 
 config MX6D
 	bool