Docs: Fix spelling typos

Signed-off-by: Antonio de Angelis <antonio.deangelis@arm.com>
Change-Id: Ie7729b848b7284696d9b546b676cb4f31ab5db47
diff --git a/docs/glossary.rst b/docs/glossary.rst
index 5a9014b..f2b9083 100644
--- a/docs/glossary.rst
+++ b/docs/glossary.rst
@@ -26,7 +26,7 @@
         in a Secure Partition.
 
     NSPE
-        Non Secure Processing Enviroment:
+        Non Secure Processing Environment:
         `PSA term`_. In TF-M this means non secure domain typically running an
         OS using services provided by TF-M.