watchdog: add amlogic watchdog support

Add support for hardware watchdog timer for Amlogic SoCs.
This driver has been heavily inspired by his Linux equivalent
(meson_gxbb_wdt.c).

Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>

Signed-off-by: Philippe Boos <pboos@baylibre.com>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/doc/board/amlogic/index.rst b/doc/board/amlogic/index.rst
index 9c7fadf..cc2ba50 100644
--- a/doc/board/amlogic/index.rst
+++ b/doc/board/amlogic/index.rst
@@ -73,6 +73,8 @@
 +-------------------------------+-----------+-----------------+--------------+-------------+------------+-------------+--------------+
 | PCIe (+NVMe)                  | *N/A*     | *N/A*           | *N/A*        | **Yes**     | **Yes**    | **Yes**     | **Yes**      |
 +-------------------------------+-----------+-----------------+--------------+-------------+------------+-------------+--------------+
+| Watchdog                      | *N/A*     | **Yes**         | *N/A*        | *N/A*       | *N/A*      | *N/A*       | *N/A*        |
++-------------------------------+-----------+-----------------+--------------+-------------+------------+-------------+--------------+
 
 Boot Documentation
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