cpumask: Move CONFIG_DEBUG_PER_CPU_MAPS into generic Kconfig

There's nothing x86-specific about it any more.  Also clarify
description.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 arch/x86/Kconfig.debug |   12 ------------
 lib/Kconfig.debug      |   12 ++++++++++++
 2 files changed, 12 insertions(+), 12 deletions(-)

diff -r 5b093f7262c1 arch/x86/Kconfig.debug
--- a/arch/x86/Kconfig.debug	Thu Nov 20 00:26:24 2008 +1030
+++ b/arch/x86/Kconfig.debug	Thu Nov 20 00:30:04 2008 +1030
@@ -79,18 +79,6 @@
 	  Unmap pages from the kernel linear mapping after free_pages().
 	  This results in a large slowdown, but helps to find certain types
 	  of memory corruptions.
-
-config DEBUG_PER_CPU_MAPS
-	bool "Debug access to per_cpu maps"
-	depends on DEBUG_KERNEL
-	depends on X86_SMP
-	default n
-	help
-	  Say Y to verify that the per_cpu map being accessed has
-	  been setup.  Adds a fair amount of code to kernel memory
-	  and decreases performance.
-
-	  Say N if unsure.
 
 config X86_PTDUMP
 	bool "Export kernel pagetable layout to userspace via debugfs"
diff -r 5b093f7262c1 lib/Kconfig.debug
--- a/lib/Kconfig.debug	Thu Nov 20 00:26:24 2008 +1030
+++ b/lib/Kconfig.debug	Thu Nov 20 00:30:04 2008 +1030
@@ -545,6 +545,18 @@
 
 	  If unsure, say N.
 
+config DEBUG_PER_CPU_MAPS
+	bool "Debug access to per_cpu maps"
+	depends on DEBUG_KERNEL
+	default n
+	help
+	  Say Y to verify that the per_cpu map being accessed has been
+	  setup and that all accesses are < nr_cpu_ids, etc.  Adds a
+	  fair amount of code to kernel memory and decreases
+	  performance.
+
+	  Say N if unsure.
+
 config FRAME_POINTER
 	bool "Compile the kernel with frame pointers"
 	depends on DEBUG_KERNEL && \