First check in the function is if swsci() is supported. All the error
paths are easy to figure out the reason, so remove the extra debug
message: it's normal not to support swsci() e.g. in dgfx.
v2: Rather than special case dgfx, just remove the debug message
    (from Ville)
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201027044618.719064-2-lucas.demarchi@intel.com
        int ret;
 
        ret = swsci(dev_priv, SWSCI_GBDA_PANEL_DETAILS, 0x0, &panel_details);
-       if (ret) {
-               drm_dbg_kms(&dev_priv->drm,
-                           "Failed to get panel details from OpRegion (%d)\n",
-                           ret);
+       if (ret)
                return ret;
-       }
 
        ret = (panel_details >> 8) & 0xff;
        if (ret > 0x10) {