Qt5: fix color bits interpretation for 32bit ARGB image formats

Change-Id: Iea8547089a0ce2dc9f6a06b84552f4261fbfa0f1
Reviewed-on: https://gerrit.libreoffice.org/65311
Tested-by: Jenkins
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>

vcl/qt5/Qt5Bitmap.cxx

@@ -267,7 +267,11 @@ BitmapBuffer* Qt5Bitmap::AcquireBuffer(BitmapAccessMode /*nMode*/)
             break;
         case 32:
         {
+#ifdef OSL_BIGENDIAN
             pBuffer->mnFormat = ScanlineFormat::N32BitTcArgb | ScanlineFormat::TopDown;
+#else
+            pBuffer->mnFormat = ScanlineFormat::N32BitTcBgra | ScanlineFormat::TopDown;
+#endif
             pBuffer->maPalette = aEmptyPalette;
             break;
         }