build(cmake): add linker script helper

Like preprocessing, CMake offers no official way to apply custom linker
scripts to executables. This commit adds a helper function to apply a
linker script to a given binary target, optionally preprocessing it
beforehand.

Change-Id: I6ed09720a8f768cf5330171365eb10f9a4c5057c
Signed-off-by: Chris Kay <chris.kay@arm.com>
diff --git a/docs/cmake/manual/module/external/ArmTargetLinkerScript.rst b/docs/cmake/manual/module/external/ArmTargetLinkerScript.rst
new file mode 100644
index 0000000..4de1066
--- /dev/null
+++ b/docs/cmake/manual/module/external/ArmTargetLinkerScript.rst
@@ -0,0 +1,5 @@
+.. cmake-module:: ../../../../../cmake/Modules/ArmTargetLinkerScript.cmake
+
+--------------
+
+*Copyright (c) 2021, Arm Limited and Contributors. All rights reserved.*