mmc: atmel: Fix clock configuration

After silencing the prints which were generated when reconfiguring the
clock of the SD/MMC bus, surprisingly, the driver stopped working such
that every attempt to use the SD/MMC bus caused the CPU to get totally
stuck hard. It turns out that the prints generated a short delay, which
was necessary for the CPU to reconfigure the clock without getting stuck.
Thus, this patch adds a short delay after the clock configuration instead.
Signed-off-by: NMarek Vasut <marex@denx.de>
Reviewed-by: NAndreas Bießmann <andreas.devel@googlemail.com>

drivers/mmc/gen_atmel_mci.c

@@ -113,6 +113,8 @@ static void mci_set_mode(struct mmc *mmc, u32 hz, u32 blklen)
 	if (mmc->card_caps & mmc->cfg->host_caps & MMC_MODE_HS)
 		writel(MMCI_BIT(HSMODE), &mci->cfg);
 
+	udelay(50);
+
 	initialized = 1;
 }