drm/i915: Fix enum pipe vs. enum transcoder for the PCH transcoder

drm/i915: Fix enum pipe vs. enum transcoder for the PCH transcoder

commit 41c32e5da3ff3922490341a988b2a3ae46d0b6a8 upstream.

Use enum pipe for PCH transcoders also in the FIFO underrun code.

Fixes the following new sparse warnings:
intel_fifo_underrun.c:340:49: warning: mixing different enum types
intel_fifo_underrun.c:340:49:     int enum pipe  versus
intel_fifo_underrun.c:340:49:     int enum transcoder
intel_fifo_underrun.c:344:49: warning: mixing different enum types
intel_fifo_underrun.c:344:49:     int enum pipe  versus
intel_fifo_underrun.c:344:49:     int enum transcoder
intel_fifo_underrun.c:397:57: warning: mixing different enum types
intel_fifo_underrun.c:397:57:     int enum pipe  versus
intel_fifo_underrun.c:397:57:     int enum transcoder
intel_fifo_underrun.c:398:17: warning: mixing different enum types
intel_fifo_underrun.c:398:17:     int enum pipe  versus
intel_fifo_underrun.c:398:17:     int enum transcoder

Cc: Matthias Kaehlcke <mka@chromium.org>
Fixes: a21960339c8c ("drm/i915: Consistently use enum pipe for PCH transcoders")
Signed-off-by: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170901143123.7590-3-ville.syrjala@linux.intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
[nc: Backport to 4.9, drop unneeded hunks]
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>