Bump library and so versions for 3.2.0 release

Signed-off-by: Paul Elliott <paul.elliott@arm.com>
diff --git a/CMakeLists.txt b/CMakeLists.txt
index b97368f..2610359 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -348,7 +348,7 @@
     write_basic_package_version_file(
         "cmake/MbedTLSConfigVersion.cmake"
             COMPATIBILITY SameMajorVersion
-            VERSION 3.1.0)
+            VERSION 3.2.0)
 
     install(
         FILES "${CMAKE_CURRENT_BINARY_DIR}/cmake/MbedTLSConfig.cmake"