drm/i915: Remove WA_(SET|CLR)_BIT

These macros are of dubious merit when coupled with the per-context w/a
set. Instead of tweaking the value in the context, they tweak the value
based on the mmio at the time of recording; they are almost by
definition not per-context! Having removed the last users, remove the
macros to avoid temptation in the future.

v2: Kill WA_WRITE as well (now also unused).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171004124153.14142-2-chris@chris-wilson.co.uk
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>

drivers/gpu/drm/i915/intel_engine_cs.c

@@ -830,11 +830,6 @@ static int wa_add(struct drm_i915_private *dev_priv,
 #define WA_SET_FIELD_MASKED(addr, mask, value) \
 	WA_REG(addr, mask, _MASKED_FIELD(mask, value))
 
-#define WA_SET_BIT(addr, mask) WA_REG(addr, mask, I915_READ(addr) | (mask))
-#define WA_CLR_BIT(addr, mask) WA_REG(addr, mask, I915_READ(addr) & ~(mask))
-
-#define WA_WRITE(addr, val) WA_REG(addr, 0xffffffff, val)
-
 static int wa_ring_whitelist_reg(struct intel_engine_cs *engine,
 				 i915_reg_t reg)
 {