drm/i915: Polish some RMWs

Doing the if-else around RMWs is kinda silly. Just set/clear the
apporiate bits with a single RMW.

Also unify the coding style a bit icl_wa_cursorclkgating() while at it.
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231121054324.9988-4-ville.syrjala@linux.intel.com

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

@@ -193,12 +193,9 @@ static bool is_hdr_mode(const struct intel_crtc_state *crtc_state)
 static void
 skl_wa_827(struct drm_i915_private *dev_priv, enum pipe pipe, bool enable)
 {
-	if (enable)
-		intel_de_rmw(dev_priv, CLKGATE_DIS_PSL(pipe),
-			     0, DUPS1_GATING_DIS | DUPS2_GATING_DIS);
-	else
-		intel_de_rmw(dev_priv, CLKGATE_DIS_PSL(pipe),
-			     DUPS1_GATING_DIS | DUPS2_GATING_DIS, 0);
+	intel_de_rmw(dev_priv, CLKGATE_DIS_PSL(pipe),
+		     DUPS1_GATING_DIS | DUPS2_GATING_DIS,
+		     enable ? DUPS1_GATING_DIS | DUPS2_GATING_DIS : 0);
 }
 
 /* Wa_2006604312:icl,ehl */
@@ -206,10 +203,9 @@ static void
 icl_wa_scalerclkgating(struct drm_i915_private *dev_priv, enum pipe pipe,
 		       bool enable)
 {
-	if (enable)
-		intel_de_rmw(dev_priv, CLKGATE_DIS_PSL(pipe), 0, DPFR_GATING_DIS);
-	else
-		intel_de_rmw(dev_priv, CLKGATE_DIS_PSL(pipe), DPFR_GATING_DIS, 0);
+	intel_de_rmw(dev_priv, CLKGATE_DIS_PSL(pipe),
+		     DPFR_GATING_DIS,
+		     enable ? DPFR_GATING_DIS : 0);
 }
 
 /* Wa_1604331009:icl,jsl,ehl */
@@ -217,7 +213,8 @@ static void
 icl_wa_cursorclkgating(struct drm_i915_private *dev_priv, enum pipe pipe,
 		       bool enable)
 {
-	intel_de_rmw(dev_priv, CLKGATE_DIS_PSL(pipe), CURSOR_GATING_DIS,
+	intel_de_rmw(dev_priv, CLKGATE_DIS_PSL(pipe),
+		     CURSOR_GATING_DIS,
 		     enable ? CURSOR_GATING_DIS : 0);
 }