lib: rational: Move the Kconfigs into the correct place

These should not be part of the 'system tables' menu. Move them outside
on their own.

Signed-off-by: Simon Glass <sjg@chromium.org>
Fixes: 7d0f3fbb93c ("lib: rational: copy the rational fraction lib...")
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/lib/Kconfig b/lib/Kconfig
index 42e559a..9addcfa 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -989,6 +989,8 @@
 	  See also SMBIOS_SYSINFO which allows SMBIOS values to be provided in
 	  the devicetree.
 
+endmenu
+
 config LIB_RATIONAL
 	bool "enable continued fraction calculation routines"
 
@@ -996,8 +998,6 @@
 	bool "enable continued fraction calculation routines for SPL"
 	depends on SPL
 
-endmenu
-
 config ASN1_COMPILER
 	bool
 	help