am335x_evm: mmc: do not define DM_MMC for spl

Since spl doesn't support DM currently, do not define DM_MMC
for spl build.

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

include/configs/am335x_evm.h

@@ -351,6 +351,14 @@
 #define CONFIG_G_DNL_MANUFACTURER "Texas Instruments"
 #endif /* CONFIG_USB_MUSB_GADGET */
 
+/*
+ * Disable MMC DM for SPL build and can be re-enabled after adding
+ * DM support in SPL
+ */
+#ifdef CONFIG_SPL_BUILD
+#undef CONFIG_DM_MMC
+#endif
+
 #if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_USBETH_SUPPORT)
 /* Remove other SPL modes. */
 #undef CONFIG_SPL_YMODEM_SUPPORT