doc: board: Add Intel Galileo board doc

This extracts Intel Galileo 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>
diff --git a/doc/board/intel/galileo.rst b/doc/board/intel/galileo.rst
new file mode 100644
index 0000000..f51a06b
--- /dev/null
+++ b/doc/board/intel/galileo.rst
@@ -0,0 +1,22 @@
+.. SPDX-License-Identifier: GPL-2.0+
+.. sectionauthor:: Bin Meng <bmeng.cn@gmail.com>
+
+Galileo
+=======
+
+Only one binary blob is needed for Remote Management Unit (RMU) within Intel
+Quark SoC. Not like FSP, U-Boot does not call into the binary. The binary is
+needed by the Quark SoC itself.
+
+You can get the binary blob from Quark Board Support Package from Intel website:
+
+   * ./QuarkSocPkg/QuarkNorthCluster/Binary/QuarkMicrocode/RMU.bin
+
+Rename the file and put it to the board directory by::
+
+   $ cp RMU.bin board/intel/galileo/rmu.bin
+
+Now you can build U-Boot and obtain u-boot.rom::
+
+   $ make galileo_defconfig
+   $ make all