module: move CONFIG_UNUSED_SYMBOLS to the sub-menu of MODULES

When CONFIG_MODULES is disabled, CONFIG_UNUSED_SYMBOLS is pointless,
thus it should be invisible.

Instead of adding "depends on MODULES", I moved it to the sub-menu
"Enable loadable module support", which is a better fit. I put it
close to TRIM_UNUSED_KSYMS because it depends on !UNUSED_SYMBOLS.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>

init/Kconfig

@@ -2130,6 +2130,22 @@ config MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
 
 	  If unsure, say N.
 
+config UNUSED_SYMBOLS
+	bool "Enable unused/obsolete exported symbols"
+	default y if X86
+	help
+	  Unused but exported symbols make the kernel needlessly bigger.  For
+	  that reason most of these unused exports will soon be removed.  This
+	  option is provided temporarily to provide a transition period in case
+	  some external kernel module needs one of these symbols anyway. If you
+	  encounter such a case in your module, consider if you are actually
+	  using the right API.  (rationale: since nobody in the kernel is using
+	  this in a module, there is a pretty good chance it's actually the
+	  wrong interface to use).  If you really need the symbol, please send a
+	  mail to the linux kernel mailing list mentioning the symbol and why
+	  you really need it, and what the merge plan to the mainline kernel for
+	  your module is.
+
 config TRIM_UNUSED_KSYMS
 	bool "Trim unused exported kernel symbols"
 	depends on !UNUSED_SYMBOLS

lib/Kconfig.debug

@@ -277,22 +277,6 @@ config READABLE_ASM
           to keep kernel developers who have to stare a lot at assembler listings
           sane.
 
-config UNUSED_SYMBOLS
-	bool "Enable unused/obsolete exported symbols"
-	default y if X86
-	help
-	  Unused but exported symbols make the kernel needlessly bigger.  For
-	  that reason most of these unused exports will soon be removed.  This
-	  option is provided temporarily to provide a transition period in case
-	  some external kernel module needs one of these symbols anyway. If you
-	  encounter such a case in your module, consider if you are actually
-	  using the right API.  (rationale: since nobody in the kernel is using
-	  this in a module, there is a pretty good chance it's actually the
-	  wrong interface to use).  If you really need the symbol, please send a
-	  mail to the linux kernel mailing list mentioning the symbol and why
-	  you really need it, and what the merge plan to the mainline kernel for
-	  your module is.
-
 config DEBUG_FS
 	bool "Debug Filesystem"
 	help