Platform: Add full support for PSoC64 platform

Add support for the Cypress CYS0644ABZI-S2D44 board.

This support was developed over the course of 2019 in
the feature-twincpu branch. Full commit history is
available there.

Signed-off-by: Chris Brand <chris.brand@cypress.com>
Change-Id: I709633d04227b71aea87aee84fd63a48c7d26fb1
diff --git a/docs/user_guides/tfm_secure_boot.rst b/docs/user_guides/tfm_secure_boot.rst
index 3c63258..d36c428 100644
--- a/docs/user_guides/tfm_secure_boot.rst
+++ b/docs/user_guides/tfm_secure_boot.rst
@@ -239,6 +239,8 @@
 +----------+-----------------+---------------+----------+-------------+-----------------+
 | AN524    | Yes             | No            | No       | Yes         | No              |
 +----------+-----------------+---------------+----------+-------------+-----------------+
+| PSoC64   | Yes             | No            | No       | No          | No              |
++----------+-----------------+---------------+----------+-------------+-----------------+
 
 .. [1] To disable BL2, please turn off the ``BL2`` compiler switch in the
     build configuration file (``bl2/ext/mcuboot/MCUBootConfig.cmake``) or