x86: rename CONFIG_NONPROMISC_DEVMEM to CONFIG_PROMISC_DEVMEM

Linus observed:

> The real bug is that we shouldn't have "double negatives", and
> certainly not negative config options. Making that "promiscuous
> /dev/mem" option a negated thing as a config option was bad.

right ... lets rename this option. There should never be a negation
in config options.

[ that reminds me of CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER, but that
  is for another commit ;-) ]

Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index ae36bfa..f0cf5d9 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -5,10 +5,11 @@
 
 source "lib/Kconfig.debug"
 
-config NONPROMISC_DEVMEM
-	bool "Filter access to /dev/mem"
+config PROMISC_DEVMEM
+	bool "Allow unlimited access to /dev/mem"
+	default y
 	help
-	  If this option is left off, you allow userspace access to all
+	  If this option is left on, you allow userspace (root) access to all
 	  of memory, including kernel and userspace memory. Accidental
 	  access to this is obviously disastrous, but specific access can
 	  be used by people debugging the kernel.