mtd: rawnand: arasan: Ensure proper configuration for the asserted target

The controller being always asserting one CS or the other, there is no
need to actually select the right target before doing a page read/write.
However, the anfc_select_target() helper actually also changes the
timing configuration and clock in the case were two different NAND chips
with different timing requirements would be used. In this situation, we
must ensure proper configuration of the controller by calling it.

As a consequence of this change, the anfc_select_target() helper is
being moved earlier in the driver.

Fixes: 88ffef1b ("mtd: rawnand: arasan: Support the hardware BCH ECC engine")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210526093242.183847-4-miquel.raynal@bootlin.com