Prepare v2018.05-rc1

Signed-off-by: Tom Rini <trini@konsulko.com>

Makefile

@@ -3,9 +3,9 @@
 #
 
 VERSION = 2018
-PATCHLEVEL = 03
+PATCHLEVEL = 05
 SUBLEVEL =
-EXTRAVERSION =
+EXTRAVERSION = -rc1
 NAME =
 
 # *DOCUMENTATION*