x86: Remove definition of DEBUG

Defining DEBUG should only be done in development. So remove it.

Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20210114212827.47584-1-trix@redhat.com