Remove references to MBEDTLS_USER_CONFIG_VERSION

Signed-off-by: Bence Szépkúti <bence.szepkuti@arm.com>
diff --git a/ChangeLog.d/split-config.txt b/ChangeLog.d/split-config.txt
index 9a1c678..5d1201c 100644
--- a/ChangeLog.d/split-config.txt
+++ b/ChangeLog.d/split-config.txt
@@ -5,12 +5,9 @@
      change the build configuration, and should generally only be included from
      build_info.h.
    * The handling of MBEDTLS_CONFIG_FILE has been moved into build_info.h.
-   * Config file symbols MBEDTLS_CONFIG_VERSION and MBEDTLS_USER_CONFIG_VERSION
-     were introduced for use in MBEDTLS_CONFIG_FILE and
-     MBEDTLS_USER_CONFIG_FILE respectively.
-     Defining them to a particular value will ensure that mbedtls interprets
+   * A config file version symbol, MBEDTLS_CONFIG_VERSION was introduced.
+     Defining it to a particular value will ensure that mbedtls interprets
      the config file in a way that's compatible with the config file format
-     indicated by the value.
-     The config file versions are based on the value of MBEDTLS_VERSION_NUMBER
-     of the mbedtls version that first introduced that config file format.
-     The only value currently supported is 0x03000000.
+     used by the mbedtls release whose MBEDTLS_VERSION_NUMBER has the same
+     value.
+     The only value supported by mbedtls 3.0.0 is 0x03000000.
diff --git a/docs/3.0-migration-guide.d/split_config.md b/docs/3.0-migration-guide.d/split_config.md
index fc80925..b011ad7 100644
--- a/docs/3.0-migration-guide.d/split_config.md
+++ b/docs/3.0-migration-guide.d/split_config.md
@@ -9,12 +9,9 @@
 into `build_info.h`, including the handling of the `MBEDTLS_CONFIG_FILE`
 macro.
 
-Config file symbols `MBEDTLS_CONFIG_VERSION` and `MBEDTLS_USER_CONFIG_VERSION`
-were introduced for use in `MBEDTLS_CONFIG_FILE` and
-`MBEDTLS_USER_CONFIG_FILE` respectively.
-Defining them to a particular value will ensure that mbedtls interprets
+A config file version symbol, `MBEDTLS_CONFIG_VERSION` was introduced.
+Defining it to a particular value will ensure that mbedtls interprets
 the config file in a way that's compatible with the config file format
-indicated by the value.
-The config file versions are based on the value of `MBEDTLS_VERSION_NUMBER`
-of the mbedtls version that first introduced that config file format.
-The only value currently supported is `0x03000000`.
+used by the mbedtls release whose `MBEDTLS_VERSION_NUMBER` has the same
+value.
+The only value supported by mbedtls 3.0.0 is `0x03000000`.