Documentation/gpu: add some tables of contents to large documents

Some of the GPU documentation pages are quite long, with various levels
of details. Add document internal tables of contents to the larger
documents to make them easier to navigate.

The index.rst in the sub-directories have toctrees, which provide
similar overviews.

Fix one missing newline at the end of drm-uapi.rst while at it,
primarily because rst should have it, and secondarily because my editor
rst mode refuses to save the file without it.

Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://patch.msgid.link/e3f9357c0e8198cc48e69e2a3b8ca072c7ab92ca.1778238671.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Documentation/gpu/driver-uapi.rst

@@ -2,6 +2,8 @@
 DRM Driver uAPI
 ===============
 
+.. contents::
+
 drm/i915 uAPI
 =============
 

Documentation/gpu/drm-internals.rst

@@ -18,6 +18,8 @@ event handling, memory management, output management, framebuffer
 management, command submission & fencing, suspend/resume support, and
 DMA services.
 
+.. contents::
+
 Driver Initialization
 =====================
 

Documentation/gpu/drm-kms-helpers.rst

@@ -33,6 +33,8 @@ There are a few areas these helpers can grouped into:
   pipeline: Planes, handling rectangles for visibility checking and scissoring,
   flip queues and assorted bits.
 
+.. contents::
+
 Modeset Helper Reference for Common Vtables
 ===========================================
 

Documentation/gpu/drm-kms.rst

@@ -15,6 +15,8 @@ be setup by initializing the following fields.
 -  struct drm_mode_config_funcs \*funcs;
    Mode setting functions.
 
+.. contents::
+
 Overview
 ========
 

Documentation/gpu/drm-mm.rst

@@ -25,6 +25,8 @@ share it. GEM has simpler initialization and execution requirements than
 TTM, but has no video RAM management capabilities and is thus limited to
 UMA devices.
 
+.. contents::
+
 The Translation Table Manager (TTM)
 ===================================
 

Documentation/gpu/drm-ras.rst

@@ -24,6 +24,8 @@ Key Goals:
   nodes for different IP blocks, sub-blocks, or other logical subdivisions
   as applicable.
 
+.. contents::
+
 Nodes
 =====
 

Documentation/gpu/drm-uapi.rst

@@ -16,6 +16,8 @@ management, and output management.
 Cover generic ioctls and sysfs layout here. We only need high-level
 info, since man pages should cover the rest.
 
+.. contents::
+
 libdrm Device Lookup
 ====================
 
@@ -765,4 +767,4 @@ Stable uAPI events
 From ``drivers/gpu/drm/scheduler/gpu_scheduler_trace.h``
 
 .. kernel-doc::  drivers/gpu/drm/scheduler/gpu_scheduler_trace.h
-   :doc: uAPI trace events
+   :doc: uAPI trace events

Documentation/gpu/drm-usage-stats.rst

@@ -16,6 +16,8 @@ output is split between common and driver specific parts. Having said that,
 wherever possible effort should still be made to standardise as much as
 possible.
 
+.. contents::
+
 File format specification
 =========================
 

Documentation/gpu/introduction.rst

@@ -16,6 +16,8 @@ found in current kernels.
 
 [Insert diagram of typical DRM stack here]
 
+.. contents::
+
 Style Guidelines
 ================