[PATCH 2/2] Docs: Add some missing SPDX license identifiers of subsystem docs

[SeongJae Park]

Some subsystem documents are missing SPDX license identifiers.  Add
those.

Signed-off-by: SeongJae Park <sj@xxxxxxxxxx>
---
 Documentation/crypto/index.rst     | 2 ++
 Documentation/driver-api/index.rst | 2 ++
 Documentation/gpu/index.rst        | 2 ++
 Documentation/hwmon/index.rst      | 2 ++
 Documentation/input/index.rst      | 2 ++
 Documentation/mm/index.rst         | 2 ++
 Documentation/scheduler/index.rst  | 2 ++
 Documentation/sound/index.rst      | 2 ++
 8 files changed, 16 insertions(+)

diff --git a/Documentation/crypto/index.rst b/Documentation/crypto/index.rst
index da5d5ad2bdf3..95b0870e09b8 100644
--- a/Documentation/crypto/index.rst
+++ b/Documentation/crypto/index.rst
@@ -1,3 +1,5 @@
+.. SPDX-License-Identifier: GPL-2.0
+
 ==========
 Crypto API
 ==========
diff --git a/Documentation/driver-api/index.rst b/Documentation/driver-api/index.rst
index b208e0dac3a0..7a2584ab63c4 100644
--- a/Documentation/driver-api/index.rst
+++ b/Documentation/driver-api/index.rst
@@ -1,3 +1,5 @@
+.. SPDX-License-Identifier: GPL-2.0
+
 ==============================
 Driver implementer's API guide
 ==============================
diff --git a/Documentation/gpu/index.rst b/Documentation/gpu/index.rst
index eee5996acf2c..ff06a6b12c5e 100644
--- a/Documentation/gpu/index.rst
+++ b/Documentation/gpu/index.rst
@@ -1,3 +1,5 @@
+.. SPDX-License-Identifier: GPL-2.0
+
 ============================
 GPU Driver Developer's Guide
 ============================
diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index c2b3c1a822dd..2186d732654f 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -1,3 +1,5 @@
+.. SPDX-License-Identifier: GPL-2.0
+
 ===================
 Hardware Monitoring
 ===================
diff --git a/Documentation/input/index.rst b/Documentation/input/index.rst
index 35581cd18e91..d60bf9cfe005 100644
--- a/Documentation/input/index.rst
+++ b/Documentation/input/index.rst
@@ -1,3 +1,5 @@
+.. SPDX-License-Identifier: GPL-2.0
+
 ===================
 Input Documentation
 ===================
diff --git a/Documentation/mm/index.rst b/Documentation/mm/index.rst
index 5a94a921ea40..c4e9fbacaf38 100644
--- a/Documentation/mm/index.rst
+++ b/Documentation/mm/index.rst
@@ -1,3 +1,5 @@
+.. SPDX-License-Identifier: GPL-2.0
+
 ===============================
 Memory Management Documentation
 ===============================
diff --git a/Documentation/scheduler/index.rst b/Documentation/scheduler/index.rst
index 1aac972a652f..ae0229f5a9cf 100644
--- a/Documentation/scheduler/index.rst
+++ b/Documentation/scheduler/index.rst
@@ -1,3 +1,5 @@
+.. SPDX-License-Identifier: GPL-2.0
+
 =========
 Scheduler
 =========
diff --git a/Documentation/sound/index.rst b/Documentation/sound/index.rst
index 5abed5fc6485..7e67e12730d3 100644
--- a/Documentation/sound/index.rst
+++ b/Documentation/sound/index.rst
@@ -1,3 +1,5 @@
+.. SPDX-License-Identifier: GPL-2.0
+
 =============================
 Sound Subsystem Documentation
 =============================
-- 
2.25.1