[PATCH] allow hwrandom core to be a module

Despite it being small, there should be the option of making it a
module...

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Michael Buesch <mb@bu3sch.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>