Tools: Pass build configurations through header file

This patch adds a new configuration header file argument for
the manifest tool.

It is used to pass build configurations including:
- isolation level
- backend
- Configurations switches of Secure Partitions

The config file is c header with configurations defined as Macros.
The config file could be generated/maintained by all means.
In the TF-M build system, CMake generates it at build time.

Multiple config files are supported.

With the new config header, the "conditional" attributes should
not contain the "@" symbols.

And configure_file() is not required to get the values of
"conditional" attributes.

Note that configure_file() may be still performed to eliminate
CMake varibles in "manifest" attributes.

Change-Id: I9b1e4a68652c67548a079428e494e313383ec845
Signed-off-by: Kevin Peng <kevin.peng@arm.com>
diff --git a/lib/ext/tf-m-tests/repo_config_default.cmake b/lib/ext/tf-m-tests/repo_config_default.cmake
index 32b48b4..af3f796 100644
--- a/lib/ext/tf-m-tests/repo_config_default.cmake
+++ b/lib/ext/tf-m-tests/repo_config_default.cmake
@@ -8,5 +8,5 @@
 # Default configs of tf-m-tests repo
 
 set(TFM_TEST_REPO_PATH                  "DOWNLOAD"  CACHE PATH      "Path to TFM-TEST repo (or DOWNLOAD to fetch automatically")
-set(TFM_TEST_REPO_VERSION               "2a3da75"   CACHE STRING    "The version of tf-m-tests to use")
+set(TFM_TEST_REPO_VERSION               "50f26f8"   CACHE STRING    "The version of tf-m-tests to use")
 set(CMSIS_5_PATH                        "DOWNLOAD"  CACHE PATH      "Path to CMSIS_5 (or DOWNLOAD to fetch automatically")