->setup_data_interface() is a controller specific method and should
thus be placed in nand_controller_ops.
In order to make that work with controllers that support keeping
pre-configured timings we need to add a new NAND_KEEP_TIMINGS flag to
inform the core it should skip the timings selection step.
Signed-off-by: Boris Brezillon <email@example.com>
Tested-by: Janusz Krzysztofik <firstname.lastname@example.org>
Signed-off-by: Miquel Raynal <email@example.com>