usb: musb: Fix idling after host mode by increasing autosuspend delay

Looks like at least 2430 glue won't idle reliably with the 200 ms
autosuspend delay. This causes deeper idle states being blocked for
the whole SoC when disconnecting OTG A cable.

Increasing the delay to 500 ms seems to idle both MUSB and the PHY
reliably. This is probably because of time needed by the hardware
based negotiation between MUSB and the PHY.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>