x86/fpu/math-emu: Remove !NO_UNDOC_CODE

x86/fpu/math-emu: Remove !NO_UNDOC_CODE

We always want to support all FPU opcodes, including
undocumented ones. That define was fully justified ~20 years ago
but not today. Let's not complicate the code with it.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1440699330-1305-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>