mtd: spi-nor: spansion: add octal DTR support in RD_ANY_REG_OP

S28HS02GT uses RD_ANY_REG_OP to read status of each die. In Octal DTR
mode, RD_ANY_REG_OP needs dummy cycles (same as params->rdsr_dummy) and
data length should be 2.

Signed-off-by: Takahiro Kuwano <Takahiro.Kuwano@infineon.com>
Link: https://lore.kernel.org/r/20230726075257.12985-8-tudor.ambarus@linaro.org


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