mtd: spinand: winbond: Fix ODTR write VCR on W35NxxJW

In most scenarios this variant is actually unused (VCR is written in
SSDR mode), but we need to provide an octal variant. The address is 24
bits but is sent over 4 bytes MSB first. This means we need to shift the
register address by one extra byte for the address to be correct.

I didn't catch this initially because the volatile register region is
256 bytes wide, so the write-then-read procedure did work with the small
register addresses I was using at that time: 0 and 1.

Fixes: 44a2f49b9bdc ("mtd: spinand: winbond: W35N octal DTR support")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>