tree 56a09dcaa8c4f5dd3f26cccf1df4617722009d79
parent 75d9a333cef532d55c01773add6dee1106da95c3
author Darryl Green <darryl.green@arm.com> 1557403385 +0100
committer Darryl Green <darryl.green@arm.com> 1557404273 +0100

Only use submodule if present

Enabling the USE_CRYPTO_SUBMODULE option causes problems if the
crypto submodule isn't present. For example, when building
mbed-crypto as a submodule, it should use error.c from the parent
project if USE_CRYPTO_SUBMODULE is set. However if the parent
project isn't present, then the build will fail. Only enable it
if the submodule actually exists.