mmc: Allow controlling DM_MMC for VPL builds

VPL may want to use driver model for MMC even if TPL does not. Update
the rule in this driver to support that.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c
index e1110ca..a514943 100644
--- a/drivers/mmc/dw_mmc.c
+++ b/drivers/mmc/dw_mmc.c
@@ -724,7 +724,7 @@
 	return 0;
 }
 
-#ifdef CONFIG_DM_MMC
+#if CONFIG_IS_ENABLED(DM_MMC)
 int dwmci_probe(struct udevice *dev)
 {
 	struct mmc *mmc = mmc_get_mmc_dev(dev);
@@ -749,7 +749,7 @@
 		     u32 max_clk, u32 min_clk)
 {
 	cfg->name = host->name;
-#ifndef CONFIG_DM_MMC
+#if !CONFIG_IS_ENABLED(DM_MMC)
 	cfg->ops = &dwmci_ops;
 #endif
 	cfg->f_min = min_clk;