au1xxx-ide: auide_{in|out}sw() should be static

Make auide_{insw|outsw}() 'static' and mark them 'inline' as there's only one
call site for each: in the driver's {in|out}put_data() methods respectively...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>