Fix the tests build with mingw for the new Win32 APIs

Add missing library dependency of bcrypt to the tests Makefile

Signed-off-by: Simon Butcher <simon.butcher@arm.com>
diff --git a/tests/Makefile b/tests/Makefile
index 60ab27e..2249a55 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -49,7 +49,7 @@
 ifdef WINDOWS_BUILD
 DLEXT=dll
 EXEXT=.exe
-LOCAL_LDFLAGS += -lws2_32
+LOCAL_LDFLAGS += -lws2_32 -lbcrypt
 ifdef SHARED
 SHARED_SUFFIX=.$(DLEXT)
 endif