mmc: Revert "mmc: sdhci: Fix SDHCI_QUIRK_TIMEOUT_USES_SDCLK"

This reverts commit 4b01681c, which introduced a new potential
divide by zero in the process of fixing one.  The subsequent commits
attempt to fix the issue properly.
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/sdhci.c

@@ -632,9 +632,6 @@ static u8 sdhci_calc_timeout(struct sdhci_host *host, struct mmc_command *cmd)
 		target_timeout = data->timeout_ns / 1000 +
 			data->timeout_clks / host->clock;
 
-	if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)
-		host->timeout_clk = host->clock / 1000;
-
 	/*
 	 * Figure out needed cycles.
 	 * We do this in steps in order to fit inside a 32 bit int.
@@ -645,7 +642,6 @@ static u8 sdhci_calc_timeout(struct sdhci_host *host, struct mmc_command *cmd)
 	 *     =>
 	 *     (1) / (2) > 2^6
 	 */
-	BUG_ON(!host->timeout_clk);
 	count = 0;
 	current_timeout = (1 << 13) * 1000 / host->timeout_clk;
 	while (current_timeout < target_timeout) {
@@ -2474,6 +2470,9 @@ int sdhci_add_host(struct sdhci_host *host)
 	if (caps[0] & SDHCI_TIMEOUT_CLK_UNIT)
 		host->timeout_clk *= 1000;
 
+	if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)
+		host->timeout_clk = host->clock / 1000;
+
 	/*
 	 * In case of Host Controller v3.00, find out whether clock
 	 * multiplier is supported.