8255530: Additional cleanup after JDK-8235710 (elliptic curve removal)

Reviewed-by: erikj

Author: magicus

make/autoconf/spec.gmk.in

@@ -759,7 +759,6 @@ TAR_SUPPORTS_TRANSFORM:=@TAR_SUPPORTS_TRANSFORM@
 
 # Build setup
 ENABLE_AOT:=@ENABLE_AOT@
-ENABLE_INTREE_EC:=@ENABLE_INTREE_EC@
 USE_EXTERNAL_LIBJPEG:=@USE_EXTERNAL_LIBJPEG@
 USE_EXTERNAL_LIBGIF:=@USE_EXTERNAL_LIBGIF@
 USE_EXTERNAL_LIBZ:=@USE_EXTERNAL_LIBZ@