mtd: spi-nor: rename .otp_org to .otp and make it a pointer

Move the OTP ops out of the flash_info structure. Besides of saving some
space, there will be a new macro SNOR_OTP() which can be used to set the
ops:
  .otp = SNOR_OTP(...),

Signed-off-by: Michael Walle <mwalle@kernel.org>
Link: https://lore.kernel.org/r/20230807-mtd-flash-info-db-rework-v3-14-e60548861b10@kernel.org


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