drm/i915: cleanup per-pipe reg usage

We had some conversions over to the _PIPE macros, but didn't get
everything.  So hide the per-pipe regs with an _ (still used in a few
places for legacy) and add a few _PIPE based macros, then make sure
everyone uses them.

[update: remove usage of non-existent no-op macro]
[update 2: keep modesetting suspend/resume code, update to new reg names]
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
[ickle: stylistic cleanups for checkpatch and taste]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/intel_dvo.c b/drivers/gpu/drm/i915/intel_dvo.c
index ea37328..6eda1b5 100644
--- a/drivers/gpu/drm/i915/intel_dvo.c
+++ b/drivers/gpu/drm/i915/intel_dvo.c
@@ -178,7 +178,7 @@
 	int pipe = intel_crtc->pipe;
 	u32 dvo_val;
 	u32 dvo_reg = intel_dvo->dev.dvo_reg, dvo_srcdim_reg;
-	int dpll_reg = (pipe == 0) ? DPLL_A : DPLL_B;
+	int dpll_reg = DPLL(pipe);
 
 	switch (dvo_reg) {
 	case DVOA: