ABI: testing/sysfs-module: document initstate

Despite being an old ABI, present on all modules, its documentation
is missing. Add it, based on the original commit.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/b9c72187abce2b0efd1c41646b1d0c66104d90e4.1632750608.git.mchehab+huawei@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/ABI/testing/sysfs-module

@@ -41,6 +41,13 @@ KernelVersion:	3.3
 Contact:	Kay Sievers <kay.sievers@vrfy.org>
 Description:	Module size in bytes.
 
+What:		/sys/module/*/initstate
+Date:		Nov 2006
+KernelVersion:	2.6.19
+Contact:	Kay Sievers <kay.sievers@vrfy.org>
+Description:	Show the initialization state(live, coming, going) of
+		the module.
+
 What:		/sys/module/*/taint
 Date:		Jan 2012
 KernelVersion:	3.3