[PATCH] nfit: Document sysfs interface dirty_shutdown

[Dexuan Cui]

The new sysfs node was added in Sep 2018 in:
commit 0ead11181fe0 ("acpi, nfit: Collect shutdown status")

Now let's document it.

Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
---
 Documentation/ABI/testing/sysfs-bus-nfit | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-nfit b/Documentation/ABI/testing/sysfs-bus-nfit
index a1cb44dcb908..bd6cde8c0ea9 100644
--- a/Documentation/ABI/testing/sysfs-bus-nfit
+++ b/Documentation/ABI/testing/sysfs-bus-nfit
@@ -153,6 +153,14 @@ Description:
 		subsystem controller vendor.
 
 
+What:		/sys/bus/nd/devices/nmemX/nfit/dirty_shutdown
+Date:		Sep, 2018
+KernelVersion:	v4.20
+Contact:	linux-nvdimm@xxxxxxxxxxxx
+Description:
+		(RO) Unsafe Shutdown Count for the NVDIMM device.
+
+
 What:		/sys/bus/nd/devices/ndbusX/nfit/revision
 Date:		Jun, 2015
 KernelVersion:	v4.2
-- 
2.19.1