drm/i915: Pass enum pipe to intel_set_pch_fifo_underrun_reporting()

Commit a2196033 ("drm/i915: Consistently use enum pipe for PCH
transcoders") misses some pieces, due to a problem with the patch
format, this patch adds the remaining bits.

Fixes: a2196033 ("drm/i915: Consistently use enum pipe for PCH
transcoders")

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20170719173928.186638-1-mka@chromium.org