docs: xilinx: convert eemi.txt to eemi.rst

This is a very trivial conversion: adjust the title markup
and add a few literal block markups to produce a better
visual when parsed and avoid warnings.

As newer documents related to xilinx could be added in the future,
create a new index file for it.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/xilinx/eemi.txt → Documentation/xilinx/eemi.rst

----------------------------------------------------------------------
+====================================
 Xilinx Zynq MPSoC EEMI Documentation
----------------------------------------------------------------------
+====================================
 
 Xilinx Zynq MPSoC Firmware Interface
 -------------------------------------
@@ -21,7 +21,7 @@ The zynqmp-firmware driver maintain all EEMI APIs in zynqmp_eemi_ops
 structure. Any driver who want to communicate with PMC using EEMI APIs
 can call zynqmp_pm_get_eemi_ops().
 
-Example of EEMI ops:
+Example of EEMI ops::
 
 	/* zynqmp-firmware driver maintain all EEMI APIs */
 	struct zynqmp_eemi_ops {
@@ -34,7 +34,7 @@ Example of EEMI ops:
 		.query_data = zynqmp_pm_query_data,
 	};
 
-Example of EEMI ops usage:
+Example of EEMI ops usage::
 
 	static const struct zynqmp_eemi_ops *eemi_ops;
 	u32 ret_payload[PAYLOAD_ARG_CNT];

Documentation/xilinx/index.rst

+:orphan:
+
+===========
+Xilinx FPGA
+===========
+
+.. toctree::
+    :maxdepth: 1
+
+    eemi
+
+.. only::  subproject and html
+
+   Indices
+   =======
+
+   * :ref:`genindex`