Version: Update for TF-M v1.2.0 release

This patch updates the TF-M version for runtime code,
build system and documentation to v1.2.0

Signed-off-by: Minos Galanakis <minos.galanakis@arm.com>
Change-Id: I53b1e916a9928bac7347381d1a37c7d62bd2302a
diff --git a/docs/contributing/platform_deprecation.rst b/docs/contributing/platform_deprecation.rst
index 71cda15..d9d00ff 100644
--- a/docs/contributing/platform_deprecation.rst
+++ b/docs/contributing/platform_deprecation.rst
@@ -54,7 +54,7 @@
 |                              | after     |                                   |
 |                              | release   |                                   |
 +==============================+===========+===================================+
-|    mps2/an539                | 1.2       |   N.A                             |
+|    mps2/an539                | v1.2.0    |   N.A                             |
 +------------------------------+-----------+-----------------------------------+
 
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