drm/i915: Add glk to intel_detect_preproduction_hw()

Detect GLK pre-production steppings. Not 100% of A2 being pre-prod
since the spec is a bit of a mess but feels more or less correct.
Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200128155152.21977-4-ville.syrjala@linux.intel.comAcked-by: Chris Wilson <chris@chris-wilson.co.uk>

drivers/gpu/drm/i915/i915_drv.c

@@ -387,6 +387,7 @@ static void intel_detect_preproduction_hw(struct drm_i915_private *dev_priv)
 	pre |= IS_SKL_REVID(dev_priv, 0, SKL_REVID_F0);
 	pre |= IS_BXT_REVID(dev_priv, 0, BXT_REVID_B_LAST);
 	pre |= IS_KBL_REVID(dev_priv, 0, KBL_REVID_A0);
+	pre |= IS_GLK_REVID(dev_priv, 0, GLK_REVID_A2);
 
 	if (pre) {
 		drm_err(&dev_priv->drm, "This is a pre-production stepping. "

drivers/gpu/drm/i915/i915_drv.h

@@ -1554,6 +1554,8 @@ IS_SUBPLATFORM(const struct drm_i915_private *i915,
 
 #define GLK_REVID_A0		0x0
 #define GLK_REVID_A1		0x1
+#define GLK_REVID_A2		0x2
+#define GLK_REVID_B0		0x3
 
 #define IS_GLK_REVID(dev_priv, since, until) \
 	(IS_GEMINILAKE(dev_priv) && IS_REVID(dev_priv, since, until))