alpha: Fix typo in ev6-copy_user.S

Patch 85250231 introduced a typo.

That said, the identity AND insns added by that patch are more
clearly written as MOV.  At the same time, re-schedule the ev6
version so that the first dispatch can execute in parallel.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Matt Turner <mattst88@gmail.com>