build_macros.mk: include assert and define loop macros

Loop macros make it easier for developers to include new variables to
assert or define and also help code code readability on makefiles.

Change-Id: I0d21d6e67b3eca8976c4d856ac8ccc02c8bb5ffa
Signed-off-by: Leonardo Sandoval <leonardo.sandoval@linaro.org>
diff --git a/drivers/auth/mbedtls/mbedtls_common.mk b/drivers/auth/mbedtls/mbedtls_common.mk
index 94f2f59..8454105 100644
--- a/drivers/auth/mbedtls/mbedtls_common.mk
+++ b/drivers/auth/mbedtls/mbedtls_common.mk
@@ -98,10 +98,13 @@
 endif
 
 # Needs to be set to drive mbed TLS configuration correctly
-$(eval $(call add_define,TF_MBEDTLS_KEY_ALG_ID))
-$(eval $(call add_define,TF_MBEDTLS_KEY_SIZE))
-$(eval $(call add_define,TF_MBEDTLS_HASH_ALG_ID))
-$(eval $(call add_define,TF_MBEDTLS_USE_AES_GCM))
+$(eval $(call add_defines,\
+    $(sort \
+        TF_MBEDTLS_KEY_ALG_ID \
+        TF_MBEDTLS_KEY_SIZE \
+        TF_MBEDTLS_HASH_ALG_ID \
+        TF_MBEDTLS_USE_AES_GCM \
+)))
 
 $(eval $(call MAKE_LIB,mbedtls))