mmc: mmci: use NSEC_PER_SEC macro

This patch replaces a constant used in calculating timeout with a proper
macro. This is make code more readable.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/mmci.c

@@ -719,7 +719,7 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
 	data->bytes_xfered = 0;
 
 	clks = (unsigned long long)data->timeout_ns * host->cclk;
-	do_div(clks, 1000000000UL);
+	do_div(clks, NSEC_PER_SEC);
 
 	timeout = data->timeout_clks + (unsigned int)clks;