Example: Update example partition

To fix some docs and cmake issues

Change-Id: I13b486da854651839ce6ca19c8d0362ac72b02dc
Signed-off-by: Raef Coles <raef.coles@arm.com>
diff --git a/example_partition/CMakeLists.txt b/example_partition/CMakeLists.txt
index a39a69b..5fd777a 100644
--- a/example_partition/CMakeLists.txt
+++ b/example_partition/CMakeLists.txt
@@ -1,5 +1,5 @@
 #-------------------------------------------------------------------------------
-# Copyright (c) 2020, Arm Limited. All rights reserved.
+# Copyright (c) 2020-2021, Arm Limited. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -12,20 +12,23 @@
 cmake_minimum_required(VERSION 3.15)
 cmake_policy(SET CMP0079 NEW)
 
-add_library(tfm_partition_example STATIC)
+# The name of the target is required to be of the pattern
+# tfm_app_rot_partition_x or tfm_psa_rot_partition_x, as it affects how the
+# linker script will lay the partition in memory.
+add_library(tfm_app_rot_partition_example STATIC)
 
-target_sources(tfm_partition_example
+target_sources(tfm_app_rot_partition_example
     PRIVATE
         tfm_example_partition.c
 )
 
-target_include_directories(tfm_partition_example
+target_include_directories(tfm_app_rot_partition_example
     PRIVATE
         $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
         ${CMAKE_BINARY_DIR}/generated/secure_fw/partitions/example_partition
 )
 
-target_link_libraries(tfm_partition_example
+target_link_libraries(tfm_app_rot_partition_example
     PRIVATE
         tfm_secure_api
         psa_interface
@@ -35,7 +38,7 @@
 ############################ Secure API ########################################
 
 target_sources(tfm_secure_api
-    PRIVATE
+    INTERFACE
         ${CMAKE_CURRENT_SOURCE_DIR}/tfm_example_partition_secure_api.c
 )
 
@@ -50,7 +53,7 @@
 
 target_link_libraries(tfm_partitions
     INTERFACE
-        tfm_partition_example
+        tfm_app_rot_partition_example
 )
 
 target_compile_definitions(tfm_partition_defs