programs, tests: Depend only on libmbedcrypto

Update the tests and programs to depend only on libmbedcrypto, since
we'll soon only build libmbedcrypto.
diff --git a/programs/test/CMakeLists.txt b/programs/test/CMakeLists.txt
index 2b455ee..192ac4c 100644
--- a/programs/test/CMakeLists.txt
+++ b/programs/test/CMakeLists.txt
@@ -1,5 +1,5 @@
 set(libs
-    mbedtls
+    mbedcrypto
 )
 
 add_executable(selftest selftest.c)