src/arch: Update license headers missing paragraph 2

For the coreboot license header, we want to use two paragraphs.
See the section 'Common License Header' in the coreboot wiki
for more details.

Change-Id: I4a43f3573364a17b5d7f63b1f83b8ae424981b18
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/13118
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

src/arch/x86/crt0_romcc_epilogue.inc

@@ -4,6 +4,11 @@
  * This file is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
  * published by the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
  */
 #include <cpu/x86/post_code.h>