dynamic_debug: update Documentation/*, Kconfig.debug

In dynamic-debug-howto.txt:

- add section: Debug Messages at Module Initialization Time
- update flags indicators in example outputs to include '='
- make flags descriptions tabular
- add item on '_' flag-char
- add dyndbg, boot-args examples
- rewrap some paragraphs with long lines

In Kconfig.debug, note that compiling with -DDEBUG enables all
pr_debug()s in that code.

In kernel-parameters.txt, add dyndbg and module.dyndbg items,
and deprecate ddebug_query.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/kernel-parameters.txt

@@ -610,7 +610,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 
 	ddebug_query=   [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot
 			time. See Documentation/dynamic-debug-howto.txt for
-			details.
+			details.  Deprecated, see dyndbg.
 
 	debug		[KNL] Enable kernel debugging (events log level).
 
@@ -730,6 +730,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 
 	dscc4.setup=	[NET]
 
+	dyndbg[="val"]		[KNL,DYNAMIC_DEBUG]
+	module.dyndbg[="val"]
+			Enable debug messages at boot time.  See
+			Documentation/dynamic-debug-howto.txt for details.
+
 	earlycon=	[KNL] Output early console device and options.
 		uart[8250],io,<addr>[,options]
 		uart[8250],mmio,<addr>[,options]