QUIC: Build system update

Download a single tarball with the sources of quicly and its dependencies from github instead of cloning submodules.

Change-Id: Id9955565d46f595b3a14ba3408c24045d4acd296
Signed-off-by: Aloys Augustin <aloaugus@cisco.com>
diff --git a/build/external/Makefile b/build/external/Makefile
index 084d694..aed8b2e 100644
--- a/build/external/Makefile
+++ b/build/external/Makefile
@@ -30,6 +30,7 @@
 include packages.mk
 include packages/nasm.mk
 include packages/ipsec-mb.mk
+include packages/quicly.mk
 include packages/dpdk.mk
 include packages/rdma-core.mk
 
@@ -38,7 +39,7 @@
 	@rm -rf $(B) $(I)
 
 .PHONY: install
-install: dpdk-install rdma-core-install
+install: dpdk-install rdma-core-install quicly-install
 
 .PHONY: config
 config: dpdk-config rdma-core-config