docs: add arch doc directories to the index

diff --git a/Documentation/arm/index.rst b/Documentation/arm/index.rst
index bd316d1a1802..9c2f781f4685 100644
--- a/Documentation/arm/index.rst
+++ b/Documentation/arm/index.rst

@@ -1,5 +1,3 @@
-:orphan:
-
 ================
 ARM Architecture
 ================

diff --git a/Documentation/arm64/index.rst b/Documentation/arm64/index.rst
index 018b7836ecb7..96b696ba4e6c 100644
--- a/Documentation/arm64/index.rst
+++ b/Documentation/arm64/index.rst

@@ -1,5 +1,3 @@
-:orphan:
-
 ==================
 ARM64 Architecture
 ==================

diff --git a/Documentation/ia64/index.rst b/Documentation/ia64/index.rst
index a3e3052ad6e2..ef99475f672b 100644
--- a/Documentation/ia64/index.rst
+++ b/Documentation/ia64/index.rst

@@ -1,5 +1,3 @@
-:orphan:
-
 ==================
 IA-64 Architecture
 ==================

diff --git a/Documentation/index.rst b/Documentation/index.rst
index 95db26bf2899..f898def833f4 100644
--- a/Documentation/index.rst
+++ b/Documentation/index.rst

@@ -118,7 +118,17 @@ implementation.
    :maxdepth: 2
 
    sh/index
+   arm/index
+   arm64/index
+   ia64/index
+   m68k/index
+   powerpc/index
+   riscv/index
+   s390/index
+   sh/index
+   sparc/index
    x86/index
+   xtensa/index
 
 Filesystem Documentation
 ------------------------

diff --git a/Documentation/m68k/index.rst b/Documentation/m68k/index.rst
index f3273ec075c3..3a5ba7fe1703 100644
--- a/Documentation/m68k/index.rst
+++ b/Documentation/m68k/index.rst

@@ -1,4 +1,4 @@
-:orphan:
+.. SPDX-License-Identifier: GPL-2.0
 
 =================
 m68k Architecture

diff --git a/Documentation/powerpc/index.rst b/Documentation/powerpc/index.rst
index 1ff17268db46..549b1cdd77ae 100644
--- a/Documentation/powerpc/index.rst
+++ b/Documentation/powerpc/index.rst

@@ -1,4 +1,4 @@
-:orphan:
+.. SPDX-License-Identifier: GPL-2.0
 
 =======
 powerpc

diff --git a/Documentation/riscv/index.rst b/Documentation/riscv/index.rst
index c4b906d9b5a7..e3ca0922a8c2 100644
--- a/Documentation/riscv/index.rst
+++ b/Documentation/riscv/index.rst

@@ -1,5 +1,3 @@
-:orphan:
-
 ===================
 RISC-V architecture
 ===================

diff --git a/Documentation/s390/index.rst b/Documentation/s390/index.rst
index 1a914da2a07b..4602312909d3 100644
--- a/Documentation/s390/index.rst
+++ b/Documentation/s390/index.rst

@@ -1,5 +1,3 @@
-:orphan:
-
 =================
 s390 Architecture
 =================

diff --git a/Documentation/sparc/index.rst b/Documentation/sparc/index.rst
index 91f7d6643dd5..71cff621f243 100644
--- a/Documentation/sparc/index.rst
+++ b/Documentation/sparc/index.rst

@@ -1,5 +1,3 @@
-:orphan:
-
 ==================
 Sparc Architecture
 ==================

diff --git a/Documentation/xtensa/index.rst b/Documentation/xtensa/index.rst
index 5a24e365e35f..52fa04eb39a3 100644
--- a/Documentation/xtensa/index.rst
+++ b/Documentation/xtensa/index.rst

@@ -1,4 +1,4 @@
-:orphan:
+.. SPDX-License-Identifier: GPL-2.0
 
 ===================
 Xtensa Architecture

-- 
2.21.0