mmc: mediatek: Preinitialize delay_phase in get_best_delay()

drivers/mmc/host/mtk-sd.c: In function ‘get_best_delay’:
drivers/mmc/host/mtk-sd.c:1284: warning: ‘delay_phase.start’ is used uninitialized in this function
drivers/mmc/host/mtk-sd.c:1284: warning: ‘delay_phase.maxlen’ is used uninitialized in this function

If delay is zero, these fields are indeed not initialized.
Let the compiler preinitialize the whole struct to fix this.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/mtk-sd.c

@@ -1276,7 +1276,7 @@ static struct msdc_delay_phase get_best_delay(struct msdc_host *host, u32 delay)
 	int start = 0, len = 0;
 	int start_final = 0, len_final = 0;
 	u8 final_phase = 0xff;
-	struct msdc_delay_phase delay_phase;
+	struct msdc_delay_phase delay_phase = { 0, };
 
 	if (delay == 0) {
 		dev_err(host->dev, "phase error: [map:%x]\n", delay);