ARM: kirkwood: Increase NAND chip-delay for DNS-32[05]

The default chip-delay of 25us is a bit too tight for some DNS-320's,
and D-Link seem to specify 30us in their kernels for both devices.
Increase to 35us to make sure the NAND is stable.

Signed-off-by: Jamie Lentin <jm@lentin.co.uk>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>