mmc: omap_hsmmc: use a default 52MHz max clock rate if none is specified

mmc_of_parse() doesn't set a default value if none is available in DT.
In that case, use a default 52MHz clock rate.

Signed-off-by: Alex Kiernan <alex.kiernan@gmail.com>
Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Tested-by: Adam Ford <aford173@gmail.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

drivers/mmc/omap_hsmmc.c

@@ -1832,6 +1832,8 @@ static int omap_hsmmc_ofdata_to_platdata(struct udevice *dev)
 	if (ret < 0)
 		return ret;
 
+	if (!cfg->f_max)
+		cfg->f_max = 52000000;
 	cfg->host_caps |= MMC_MODE_HS_52MHz | MMC_MODE_HS;
 	cfg->f_min = 400000;
 	cfg->voltages = MMC_VDD_32_33 | MMC_VDD_33_34 | MMC_VDD_165_195;