mtd: rawnand: marvell: Fix read logic for layouts with ->nchunks > 2

The code is doing monolithic reads for all chunks except the last one
which is wrong since a monolithic read will issue the
READ0+ADDRS+READ_START sequence. It not only takes longer because it
forces the NAND chip to reload the page content into its internal
cache, but by doing that we also reset the column pointer to 0, which
means we'll always read the first chunk instead of moving to the next
one.

Rework the code to do a monolithic read only for the first chunk,
then switch to naked reads for all intermediate chunks and finally
issue a last naked read for the last chunk.

Fixes: 02f26ecf mtd: nand: add reworked Marvell NAND controller driver
Cc: stable@vger.kernel.org
Reported-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Tested-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>