MTD: pxa3xx-nand: add devicetree bindings

This patch contains a hack to get the DMA resources of the device when
probed from a devicetree node. This can be removed once a generic DMA
controller framework lands.

A mtd_part_parser_data is passed mtd_device_parse_register which
contains a reference to the device node, so MTD partitions can be
added as children.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com>