drm/i915: Make RING_PDP relative to engine->mmio_base

The PDP registers are an oddity inside the set of context saved
registers in that they take the engine as a parameter to the macro and
not the mmio_base as the others do. Make it accept the engine->mmio_base
for consistency in programming the context registers.

add/remove: 0/0 grow/shrink: 2/1 up/down: 3/-32 (-29)
Function                                     old     new   delta
emit_ppgtt_update                            324     326      +2
capture                                     5102    5103      +1
execlists_init_reg_state.isra               1128    1096     -32

And similar savings later!

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190405123831.9724-1-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 00e0356..c18caa7 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -439,8 +439,8 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
 #define RING_PP_DIR_DCLV(base)		_MMIO((base) + 0x220)
 #define   PP_DIR_DCLV_2G		0xffffffff
 
-#define GEN8_RING_PDP_UDW(engine, n)	_MMIO((engine)->mmio_base + 0x270 + (n) * 8 + 4)
-#define GEN8_RING_PDP_LDW(engine, n)	_MMIO((engine)->mmio_base + 0x270 + (n) * 8)
+#define GEN8_RING_PDP_UDW(base, n)	_MMIO((base) + 0x270 + (n) * 8 + 4)
+#define GEN8_RING_PDP_LDW(base, n)	_MMIO((base) + 0x270 + (n) * 8)
 
 #define GEN8_R_PWR_CLK_STATE		_MMIO(0x20C8)
 #define   GEN8_RPCS_ENABLE		(1 << 31)