Merge pull request #21 from efabless/change_tag

Update Makefile
diff --git a/Makefile b/Makefile
index 84dd315..ccc8a6d 100644
--- a/Makefile
+++ b/Makefile
@@ -22,7 +22,7 @@
 # Install lite version of caravel, (1): caravel-lite, (0): caravel
 CARAVEL_LITE?=1
 
-MPW_TAG ?= mpw-5c
+MPW_TAG ?= mpw-6b
 
 ifeq ($(CARAVEL_LITE),1)
 	CARAVEL_NAME := caravel-lite