usb: musb: disable OTG AUTOIDLE only with omap3430

Omap3 MUSB AUTOIDLE functionality configured through OTG_SYSCONFIG
register prevents the device from going into retention.
This is a workaround (by Richard Woodruff/TI), as his comment :
> A new MUSB bug which is a match to data below was identified very
> recently (on hardware and in simulation).
> This bug is in 3430 and not 3630.
> As a priority test (and as new default) you should have engineers
> disable autoidle for MUSB block.
> This is the workaround which will show up in next errata.
Signed-off-by: NNiilo Minkkinen <ext-niilo.1.minkkinen@nokia.com>
Signed-off-by: NRichard Woodruff <r-woodruff2@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/usb/musb/omap2430.c

@@ -227,7 +227,12 @@ int __init musb_platform_init(struct musb *musb)
 	l &= ~AUTOIDLE;		/* disable auto idle */
 	l &= ~NOIDLE;		/* remove possible noidle */
 	l |= SMARTIDLE;		/* enable smart idle */
-	l |= AUTOIDLE;		/* enable auto idle */
+	/*
+	 * MUSB AUTOIDLE don't work in 3430.
+	 * Workaround by Richard Woodruff/TI
+	 */
+	if (!cpu_is_omap3430())
+		l |= AUTOIDLE;		/* enable auto idle */
 	omap_writel(l, OTG_SYSCONFIG);
 
 	l = omap_readl(OTG_INTERFSEL);