mtd: spi-nor: atmel: drop duplicate entry

The Atmel AT26DF321 and AT25DF321 have the same ID. Both were just
discovered by reading their IDs, that is, there is no probing by name.
Thus only the first one (the AT25DF321) in the list was ever probed.
Luckily, the AT25DF is also the newer series. Drop the AT26DF321.

Signed-off-by: Michael Walle <mwalle@kernel.org>
Link: https://lore.kernel.org/r/20230807-mtd-flash-info-db-rework-v3-40-e60548861b10@kernel.org


Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>