cmake: By default only apply patches when downloading remote libraries

By default only apply the required patches to remote libraries when they
are using the DOWNLOAD strategy.
When remote library locations are provided manually the patches
should be manually managed.
Add option to force applying patches always.

Change-Id: I7c121a70851d8545bc7e61e0022b2692157fb3ef
Signed-off-by: Joakim Andersson <joakim.andersson@nordicsemi.no>
diff --git a/lib/ext/mbedcrypto/CMakeLists.txt b/lib/ext/mbedcrypto/CMakeLists.txt
index 9316aca..34d93d4 100644
--- a/lib/ext/mbedcrypto/CMakeLists.txt
+++ b/lib/ext/mbedcrypto/CMakeLists.txt
@@ -11,6 +11,7 @@
     LIB_NAME                mbedcrypto
     LIB_SOURCE_PATH_VAR     MBEDCRYPTO_PATH
     LIB_PATCH_DIR           ${CMAKE_CURRENT_LIST_DIR}
+    LIB_FORCE_PATCH         ${MBEDCRYPTO_FORCE_PATCH}
     FETCH_CONTENT_ARGS
         GIT_REPOSITORY      ${MBEDCRYPTO_GIT_REMOTE}
         GIT_TAG             ${MBEDCRYPTO_VERSION}