Add CMake include path for generated header

Now that we are generating psa_crypto_driver_wrappers.h, we need to pass
build/library as an include directory.

Signed-off-by: David Horstmann <david.horstmann@arm.com>
diff --git a/library/CMakeLists.txt b/library/CMakeLists.txt
index 65b957a..2b1fd43 100644
--- a/library/CMakeLists.txt
+++ b/library/CMakeLists.txt
@@ -323,7 +323,9 @@
     target_include_directories(${target}
         PUBLIC $<BUILD_INTERFACE:${MBEDTLS_DIR}/include/>
                $<INSTALL_INTERFACE:include/>
-        PRIVATE ${MBEDTLS_DIR}/library/)
+        PRIVATE ${MBEDTLS_DIR}/library/
+                # Needed to include psa_crypto_driver_wrappers.h
+                ${CMAKE_CURRENT_BINARY_DIR})
     # Pass-through MBEDTLS_CONFIG_FILE and MBEDTLS_USER_CONFIG_FILE
     if(MBEDTLS_CONFIG_FILE)
         target_compile_definitions(${target}