drm/i915/cdclk: Reorder bxt_sanitize_cdclk()

Make the sequence of steps in bxt_sanitize_cdclk() more logical by
grouping things related to the check on the value of CDCLK_CTL into a
single "block". Also, this will make an upcoming change replacing that
block with a single function call easier to follow.

v2:
  - Improve body of commit message to be more self-contained.
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240105140538.183553-4-gustavo.sousa@intel.com

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

@@ -2060,13 +2060,23 @@ static void bxt_sanitize_cdclk(struct drm_i915_private *dev_priv)
 	    dev_priv->display.cdclk.hw.cdclk == dev_priv->display.cdclk.hw.bypass)
 		goto sanitize;
 
-	/* DPLL okay; verify the cdclock
-	 *
+	/* Make sure this is a legal cdclk value for the platform */
+	cdclk = bxt_calc_cdclk(dev_priv, dev_priv->display.cdclk.hw.cdclk);
+	if (cdclk != dev_priv->display.cdclk.hw.cdclk)
+		goto sanitize;
+
+	/* Make sure the VCO is correct for the cdclk */
+	vco = bxt_calc_cdclk_pll_vco(dev_priv, cdclk);
+	if (vco != dev_priv->display.cdclk.hw.vco)
+		goto sanitize;
+
+	/*
 	 * Some BIOS versions leave an incorrect decimal frequency value and
 	 * set reserved MBZ bits in CDCLK_CTL at least during exiting from S4,
 	 * so sanitize this register.
 	 */
 	cdctl = intel_de_read(dev_priv, CDCLK_CTL);
+
 	/*
 	 * Let's ignore the pipe field, since BIOS could have configured the
 	 * dividers both synching to an active pipe, or asynchronously
@@ -2074,16 +2084,6 @@ static void bxt_sanitize_cdclk(struct drm_i915_private *dev_priv)
 	 */
 	cdctl &= ~bxt_cdclk_cd2x_pipe(dev_priv, INVALID_PIPE);
 
-	/* Make sure this is a legal cdclk value for the platform */
-	cdclk = bxt_calc_cdclk(dev_priv, dev_priv->display.cdclk.hw.cdclk);
-	if (cdclk != dev_priv->display.cdclk.hw.cdclk)
-		goto sanitize;
-
-	/* Make sure the VCO is correct for the cdclk */
-	vco = bxt_calc_cdclk_pll_vco(dev_priv, cdclk);
-	if (vco != dev_priv->display.cdclk.hw.vco)
-		goto sanitize;
-
 	if (DISPLAY_VER(dev_priv) >= 20)
 		expected = MDCLK_SOURCE_SEL_CDCLK_PLL;
 	else