Define more termios.h macros unconditionally for alpha (bug 21277)

[Adhemerval Zanella]

On 27/03/2017 12:06, Joseph Myers wrote:
> On Mon, 27 Mar 2017, Adhemerval Zanella wrote:
> 
>> LGTM.  I guess the 'POSIX.1 ...' comment is out the place then?
> 
> The comment is not wrong, but it seems inappropriate in a single 
> architecture-specific file when the point of the comment seems to be to 
> relate to the removed #ifdef.
> 

Fair enough.