dm: mmc: omap_hsmmc: Add pre-reloc flag to the driver

For platforms that don't use device tree in SPL the only
way to mark this driver as 'required by relocation' is
with the DM_FLAG_PRE_RELOC flag. Add this to ensure that
the driver is bound.

Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>

drivers/mmc/omap_hsmmc.c

@@ -903,5 +903,6 @@ U_BOOT_DRIVER(omap_hsmmc) = {
 #endif
 	.probe	= omap_hsmmc_probe,
 	.priv_auto_alloc_size = sizeof(struct omap_hsmmc_data),
+	.flags	= DM_FLAG_PRE_RELOC,
 };
 #endif