kmemleak: Add support for memory hotplug

Ensure that memory hotplug can co-exist with kmemleak
by taking the hotplug lock before scanning the memory
banks.

Change-Id: Ice6e5eaac45b4d71848ff1d3f30d468c1f088232
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index c6b006a..6a9e368 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -413,7 +413,7 @@
 
 config DEBUG_KMEMLEAK
 	bool "Kernel memory leak detector"
-	depends on DEBUG_KERNEL && EXPERIMENTAL && !MEMORY_HOTPLUG && \
+	depends on DEBUG_KERNEL && EXPERIMENTAL && \
 		(X86 || ARM || PPC || MIPS || S390 || SPARC64 || SUPERH || MICROBLAZE || TILE)
 
 	select DEBUG_FS