x86/vm86: Clean up vm86.h includes

vm86.h was being implicitly included in alot of places via
processor.h, which in turn got it from math_emu.h.  Break that
chain and explicitly include vm86.h in all files that need it.
Also remove unused vm86 field from math_emu_info.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
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/1438148483-11932-7-git-send-email-brgerst@gmail.com
[ Fixed build failure. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/syscalls.h

@@ -37,6 +37,7 @@ asmlinkage long sys_get_thread_area(struct user_desc __user *);
 asmlinkage unsigned long sys_sigreturn(void);
 
 /* kernel/vm86_32.c */
+struct vm86_struct;
 asmlinkage long sys_vm86old(struct vm86_struct __user *);
 asmlinkage long sys_vm86(unsigned long, unsigned long);