mtd: rawnand: qcom: Use u8 instead of uint8_t

Fix the following checkpatch warning:
    "CHECK: Prefer kernel type 'u8' over 'uint8_t'"

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://lore.kernel.org/linux-mtd/20230716144612.32132-3-miquel.raynal@bootlin.com