drm/i915/cdclk: Only compute squash waveform when necessary

It is no use computing the squash waveform if we are not going to use
it. Move the call to cdclk_squash_waveform() inside the block guarded by
HAS_CDCLK_SQUASH(dev_priv).

v2:
  - Move "u16 waveform" declaration to inside the block where it is
    initialized and used. (Matt)
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240312163639.172321-4-gustavo.sousa@intel.comSigned-off-by: Lucas De Marchi <lucas.demarchi@intel.com>

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

@@ -2006,7 +2006,6 @@ static void _bxt_set_cdclk(struct drm_i915_private *dev_priv,
 {
 	int cdclk = cdclk_config->cdclk;
 	int vco = cdclk_config->vco;
-	u16 waveform;
 
 	if (HAS_CDCLK_CRAWL(dev_priv) && dev_priv->display.cdclk.hw.vco > 0 && vco > 0 &&
 	    !cdclk_pll_is_unknown(dev_priv->display.cdclk.hw.vco)) {
@@ -2021,10 +2020,11 @@ static void _bxt_set_cdclk(struct drm_i915_private *dev_priv,
 	} else
 		bxt_cdclk_pll_update(dev_priv, vco);
 
-	waveform = cdclk_squash_waveform(dev_priv, cdclk);
+	if (HAS_CDCLK_SQUASH(dev_priv)) {
+		u16 waveform = cdclk_squash_waveform(dev_priv, cdclk);
 
-	if (HAS_CDCLK_SQUASH(dev_priv))
 		dg2_cdclk_squash_program(dev_priv, waveform);
+	}
 
 	intel_de_write(dev_priv, CDCLK_CTL, bxt_cdclk_ctl(dev_priv, cdclk_config, pipe));