USB: fix up EHCI startup synchronization

USB: fix up EHCI startup synchronization

patch 1cb52658b4f5b10a9e91f8e1c21ca2bcc1b9a3ca in mainline.

A recent patch added software synchronization during EHCI startup,
so ports aren't switched away from the companion controllers after
resets have started.  This patch adds a short delay letting hardware
finish that port switching before any new resets begin ... so both
ends of that hardware race window are closed.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Dave Miller <davem@davemloft.net>
Cc: Dely Sy <dely.l.sy@intel.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>