drm/i915/tv: fix strncpy truncation warning

Change it to use strlcpy instead

Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180712074103.21571-1-chris@chris-wilson.co.uk


Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>