um: clean Kconfig up a bit

* kill duplicates with drivers/char/Kconfig
* take watchdog one into drivers/watchdog/Kconfig
* take mmapper to arch/um/Kconfig.um
* rename Kconfig.char menu to "UML Character Devices"

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

drivers/char/hw_random/Kconfig

@@ -222,3 +222,18 @@ config HW_RANDOM_PPC4XX
 	 module will be called ppc4xx-rng.
 
 	 If unsure, say N.
+
+config UML_RANDOM
+	depends on UML
+	tristate "Hardware random number generator"
+	help
+	  This option enables UML's "hardware" random number generator.  It
+	  attaches itself to the host's /dev/random, supplying as much entropy
+	  as the host has, rather than the small amount the UML gets from its
+	  own drivers.  It registers itself as a standard hardware random number
+	  generator, major 10, minor 183, and the canonical device name is
+	  /dev/hwrng.
+	  The way to make use of this is to install the rng-tools package
+	  (check your distro, or download from
+	  http://sourceforge.net/projects/gkernel/).  rngd periodically reads
+	  /dev/hwrng and injects the entropy into /dev/random.