drm/i915: Program CURSOR_PROGRAM and COEFF_POLARITY for icl+ combo PHYs

Bspec asks us to clear the CURSOR_PROGRAM and COEFF_POLARITY
bits in PORT_TX_DW5 on icl+ combo PHYs. Make it so.

Bspec: 21257, 49291
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250303123952.5669-2-ville.syrjala@linux.intel.com
Reviewed-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>

Author: vsyrjala

drivers/gpu/drm/i915/display/intel_combo_phy_regs.h

@@ -133,6 +133,8 @@
 #define   TX_TRAINING_EN			REG_BIT(31)
 #define   TAP2_DISABLE				REG_BIT(30)
 #define   TAP3_DISABLE				REG_BIT(29)
+#define   CURSOR_PROGRAM			REG_BIT(26)
+#define   COEFF_POLARITY			REG_BIT(25)
 #define   SCALING_MODE_SEL_MASK			REG_GENMASK(20, 18)
 #define   SCALING_MODE_SEL(x)			REG_FIELD_PREP(SCALING_MODE_SEL_MASK, (x))
 #define   RTERM_SELECT_MASK			REG_GENMASK(5, 3)

drivers/gpu/drm/i915/display/intel_ddi.c

@@ -1193,7 +1193,8 @@ static void icl_ddi_combo_vswing_program(struct intel_encoder *encoder,
 	/* Set PORT_TX_DW5 */
 	val = intel_de_read(dev_priv, ICL_PORT_TX_DW5_LN(0, phy));
 	val &= ~(SCALING_MODE_SEL_MASK | RTERM_SELECT_MASK |
-		  TAP2_DISABLE | TAP3_DISABLE);
+		 COEFF_POLARITY | CURSOR_PROGRAM |
+		 TAP2_DISABLE | TAP3_DISABLE);
 	val |= SCALING_MODE_SEL(0x2);
 	val |= RTERM_SELECT(0x6);
 	val |= TAP3_DISABLE;