build: mlx dpdk-rdma compatibility matrix

- Verify mlx_rdma_dpdk_matrix.txt versions,
  build MLX drivers in dpdk if the versions match.
  Also output version comparison results to a file
  for CI job to send notification email when the
  versions do not match.

Change-Id: Id1384ba4ea4b1f855f4d77d1d8e2c38683abfe1f
Type: improvement
Signed-off-by: Mohammed Hawari <mohammed@hawari.fr>
Signed-off-by: Dave Wallace <dwallacelf@gmail.com>
diff --git a/build/external/packages.mk b/build/external/packages.mk
index 005c2a9..99322ae 100644
--- a/build/external/packages.mk
+++ b/build/external/packages.mk
@@ -146,5 +146,9 @@
 .PHONY: $1-install
 $1-install: $(B)/.$1.install.ok
 
+.PHONY: $1-show-%
+$1-show-%:
+	@echo $$($$*)
+
 ALL_TARGETS += $1-install
 endef