usb: hub: Prevent hub autosuspend if usbcore.autosuspend is -1

If user specifies that USB autosuspend must be disabled by module
parameter "usbcore.autosuspend=-1" then we must prevent
autosuspend of USB hub devices as well.

commit 596d789a introduced in v3.8 changed the original behaivour
and stopped respecting the usbcore.autosuspend parameter for hubs.

Fixes: 596d789a "USB: set hub's default autosuspend delay as 0"

Cc: [3.8+] <stable@vger.kernel.org>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Tested-by: Michael Welling <mwelling@emacinc.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>