docs: extend deprecation policy

Our process documentation already mentions that if a platform is no
longer maintained, it is best to deprecate it to keep the project's
source tree clean and healthy.

The same argument stands for drivers or library interfaces so extend
this policy to those.

Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
Change-Id: Ieb235d6a1fb089343e0e1e3e5f36067552f2f8f0
diff --git a/docs/process/platform-ports-policy.rst b/docs/process/platform-ports-policy.rst
index b296a5f..02eb6bd 100644
--- a/docs/process/platform-ports-policy.rst
+++ b/docs/process/platform-ports-policy.rst
@@ -32,20 +32,19 @@
 deprecated interfaces. Platforms are expected to migrate before the removal of
 the deprecated interface.
 
-Platform deprecation policy
----------------------------
+Deprecation policy
+------------------
 
-If a platform is no longer maintained, it is best to deprecate it to keep the
-projects' source tree clean and healthy. Deprecation can be a 1-stage or 2-stage
-process (up to the platform maintainers).
+If a platform, driver or library interface is no longer maintained, it is best
+to deprecate it to keep the projects' source tree clean and healthy. Deprecation
+can be a 1-stage or 2-stage process (up to the maintainers).
 
- - *2-stage*: The platform's source code can be kept in the repository for a
-   cooling off period before deleting it (typically 2 release cycles). In this
-   case, we keep track ot the *Deprecated* version separately from the *Deleted*
-   version.
+ - *2-stage*: The source code can be kept in the repository for a cooling off
+   period before deleting it (typically 2 release cycles). In this case, we keep
+   track of the *Deprecated* version separately from the *Deleted* version.
 
- - *1-stage*: The platform's source code can be deleted straight away. In this
-   case, both versions are the same.
+ - *1-stage*: The source code can be deleted straight away. In this case, both
+   versions are the same.
 
 The :ref:`Platform Ports` page provides a list of all deprecated/deleted
 platform ports (or soon to be) to this day.