padata: Generic parallelization/serialization interface

This patch introduces an interface to process data objects
in parallel. The parallelized objects return after serialization
in the same order as they were before the parallelization.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

init/Kconfig

@@ -1252,4 +1252,8 @@ source "block/Kconfig"
 config PREEMPT_NOTIFIERS
 	bool
 
+config PADATA
+	depends on SMP
+	bool
+
 source "kernel/Kconfig.locks"