IDE: fix bug in reset sequence

According to the ata (ata5) specification the RESET- signal
shall be asserted for at least 25 us. Without this patch,
the RESET- signal is asserted on some boards for only < 1 us
(e. g. on the TQM5200). This patch adds a general delay of
25 us to the RESET- signal.

Without this patch a Platinum 4 GiB CF card is not recognised
properly on boards with a TQM5200 (STK52xx, TB5200).

Signed-off-by: Martin Krause <martin.krause@tqs.de>

common/cmd_ide.c

@@ -1529,6 +1529,9 @@ static void ide_reset (void)
 
 	ide_set_reset (1); /* assert reset */
 
+	/* the reset signal shall be asserted for et least 25 us */
+	udelay(25);
+
 	WATCHDOG_RESET();
 
 #ifdef CFG_PB_12V_ENABLE