mtd: rawnand: qcom: Use EOPNOTSUPP instead of ENOTSUPP

Checkpatch complains over the usage of ENOTSUPP for new patches as below:

WARNING: ENOTSUPP is not a SUSV4 error code, prefer EOPNOTSUPP

So let's fix the error code which is already present in qcom_check_op().

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230805174146.57006-6-manivannan.sadhasivam@linaro.org