Build: Improve dependency version handling

Add version variable for tf-m-tests, and update handling so that the
version variable always corresponds exactly to the git tag/hash/branch

Change-Id: Id4fe50487c599b12640704eb1bde79117c79db19
Signed-off-by: Raef Coles <raef.coles@arm.com>
diff --git a/config/config_default.cmake b/config/config_default.cmake
index 648c357..065a74a 100644
--- a/config/config_default.cmake
+++ b/config/config_default.cmake
@@ -123,12 +123,13 @@
 ################################## Dependencies ################################
 
 set(MBEDCRYPTO_PATH                     "DOWNLOAD"  CACHE PATH      "Path to Mbed Crypto (or DOWNLOAD to fetch automatically")
-set(MBEDCRYPTO_VERSION                  "2.23.0"    CACHE STRING    "The version of Mbed Crypto to use")
+set(MBEDCRYPTO_VERSION                  "mbedtls-2.23.0" CACHE STRING "The version of Mbed Crypto to use")
 set(MBEDCRYPTO_BUILD_TYPE               "${CMAKE_BUILD_TYPE}" CACHE STRING "Build type of Mbed Crypto library")
 set(TFM_MBEDCRYPTO_CONFIG_PATH          "${CMAKE_SOURCE_DIR}/lib/ext/mbedcrypto/mbedcrypto_config/tfm_mbedcrypto_config_default.h" CACHE PATH "Config to use for Mbed Crypto")
 set(TFM_MBEDCRYPTO_PLATFORM_EXTRA_CONFIG_PATH "" CACHE PATH "Config to append to standard Mbed Crypto config, used by platforms to cnfigure feature support")
 
 set(TFM_TEST_REPO_PATH                  "DOWNLOAD"  CACHE PATH      "Path to TFM-TEST repo (or DOWNLOAD to fetch automatically")
+set(TFM_TEST_REPO_VERSION               "master"    CACHE PATH      "The version of tf-m-tests to use")
 set(CMSIS_5_PATH                        "DOWNLOAD"  CACHE PATH      "Path to CMSIS_5 (or DOWNLOAD to fetch automatically")
 
 set(MCUBOOT_PATH                        "DOWNLOAD"  CACHE PATH      "Path to MCUboot (or DOWNLOAD to fetch automatically")