doc: board: Add Google Chromebook Link board doc

This extracts Google Chromebook Link board specific information from
README.x86, converts plain text documentation to reST format and
adds it to Sphinx TOC tree. No essential content change.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>

doc/README.x86

@@ -65,37 +65,6 @@ Both tell the Makefile to build u-boot.rom as a target.
 
 ---
 
-Chromebook Link specific instructions for bare mode:
-
-First, you need the following binary blobs:
-
-* descriptor.bin - Intel flash descriptor
-* me.bin - Intel Management Engine
-* mrc.bin - Memory Reference Code, which sets up SDRAM
-* video ROM - sets up the display
-
-You can get these binary blobs by:
-
-$ git clone http://review.coreboot.org/p/blobs.git
-$ cd blobs
-
-Find the following files:
-
-* ./mainboard/google/link/descriptor.bin
-* ./mainboard/google/link/me.bin
-* ./northbridge/intel/sandybridge/systemagent-r6.bin
-
-The 3rd one should be renamed to mrc.bin.
-As for the video ROM, you can get it here [3] and rename it to vga.bin.
-Make sure all these binary blobs are put in the board directory.
-
-Now you can build U-Boot and obtain u-boot.rom:
-
-$ make chromebook_link_defconfig
-$ make all
-
----
-
 Chromebook Samus (2015 Pixel) instructions for bare mode:
 
 First, you need the following binary blobs:

doc/board/google/chromebook_link.rst

@@ -0,0 +1,34 @@
+.. SPDX-License-Identifier: GPL-2.0+
+.. sectionauthor:: Simon Glass <sjg@chromium.org>
+
+Chromebook Link
+===============
+
+First, you need the following binary blobs:
+
+   * descriptor.bin - Intel flash descriptor
+   * me.bin - Intel Management Engine
+   * mrc.bin - Memory Reference Code, which sets up SDRAM
+   * video ROM - sets up the display
+
+You can get these binary blobs by::
+
+   $ git clone http://review.coreboot.org/p/blobs.git
+   $ cd blobs
+
+Find the following files:
+
+   * ./mainboard/google/link/descriptor.bin
+   * ./mainboard/google/link/me.bin
+   * ./northbridge/intel/sandybridge/systemagent-r6.bin
+
+The 3rd one should be renamed to mrc.bin.
+As for the video ROM, you can get it `here`_ and rename it to vga.bin.
+Make sure all these binary blobs are put in the board directory.
+
+Now you can build U-Boot and obtain u-boot.rom::
+
+   $ make chromebook_link_defconfig
+   $ make all
+
+.. _here: http://www.coreboot.org/~stepan/pci8086,0166.rom

doc/board/google/index.rst

@@ -0,0 +1,9 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+Google
+======
+
+.. toctree::
+   :maxdepth: 2
+
+   chromebook_link

doc/board/index.rst

@@ -6,4 +6,5 @@ Board-specific doc
 .. toctree::
    :maxdepth: 2
 
+   google/index
    intel/index