[frr] Update FRR build to include version tags (#4172)

Signed-off-by: Danny Allen <[email protected]>

Author: daall

rules/frr.mk

@@ -4,7 +4,7 @@ FRR_VERSION = 7.2.1
 FRR_SUBVERSION = 0
 FRR_BRANCH = frr/7.2
 FRR_TAG = frr-7.2.1-s2
-export FRR_VERSION FRR_SUBVERSION FRR_BRANCH
+export FRR_VERSION FRR_SUBVERSION FRR_BRANCH FRR_TAG
 
 
 FRR = frr_$(FRR_VERSION)-sonic-$(FRR_SUBVERSION)_$(CONFIGURED_ARCH).deb