Prepare v2018.09-rc2

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/Makefile b/Makefile
index 884b7d9..2f79204 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,7 @@
 VERSION = 2018
 PATCHLEVEL = 09
 SUBLEVEL =
-EXTRAVERSION = -rc1
+EXTRAVERSION = -rc2
 NAME =
 
 # *DOCUMENTATION*