treewide: Try to avoid the preprocessor with OF_REAL

Convert some of these occurences to C code, where it is easy to do. This
should help encourage this approach to be used in new code.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/mmc/rockchip_dw_mmc.c b/drivers/mmc/rockchip_dw_mmc.c
index fa297a0..855c0e7 100644
--- a/drivers/mmc/rockchip_dw_mmc.c
+++ b/drivers/mmc/rockchip_dw_mmc.c
@@ -52,10 +52,12 @@
 
 static int rockchip_dwmmc_of_to_plat(struct udevice *dev)
 {
-#if CONFIG_IS_ENABLED(OF_REAL)
 	struct rockchip_dwmmc_priv *priv = dev_get_priv(dev);
 	struct dwmci_host *host = &priv->host;
 
+	if (!CONFIG_IS_ENABLED(OF_REAL))
+		return 0;
+
 	host->name = dev->name;
 	host->ioaddr = dev_read_addr_ptr(dev);
 	host->buswidth = dev_read_u32_default(dev, "bus-width", 4);
@@ -95,7 +97,7 @@
 		debug("%s: 'clock-freq-min-max' property was deprecated.\n",
 		      __func__);
 	}
-#endif
+
 	return 0;
 }