alpha: Fix fall-out from disintegrating asm/system.h

alpha: Fix fall-out from disintegrating asm/system.h

commit d1b5153f3ec83789b71d64efaf2a880c8fe6358e upstream.

Commit ec2212088c42 ("Disintegrate asm/system.h for Alpha") removed
asm/system.h however arch/alpha/oprofile/common.c requires definitions
that were shifted from asm/system.h to asm/special_insns.h.  Include
that.

Signed-off-by: Michael Cree <mcree@orcon.net.nz>
Acked-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Zefan Li <lizefan@huawei.com>