mtd: sunxi_nand: Select the chip in sunxi_nand_chip_init_timings()

nand_scan_ident() leaves the chip deselected. So just issuing some commands
from the sunxi driver does not work. We need to select the chip before
writing the commands to the NAND device. This patch takes care of this.

Set the new timing on all dies implemented as suggested by Boris.

This was detected on the in-circuit ICnova-A20 SoM equipped with the
Micron MT29F32G08CBACAWP (4GiB) ONFI NAND device.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Roy Spliet <r.spliet@ultimaker.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
[Brian: fixup whitespace]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>