rndis_host: increase delay in command response loop

Some devices running some WinCE firmware (with SC_* Samsung processors
according to the SynCE project, verified on a HTC P3600 device) fail to
register because they apparently need extra time to respond correctly to
requests.  Increase the existing delay to satisfy them.  Based on code
from the SynCE project, on a suggestion of David Brownell.

This patch Works For Me(tm).

Signed-off-by: Pierre Ynard <linkfanel@yahoo.fr>
Acked-by: David Brownell <david-b@pacbell.net>
Cc: Greg KH <greg@kroah.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>