mfd: sec: Change device_type to int

Now that sec-i2c doesn't match device type by pointer casting anymore,
we can switch the device type from unsigned long to int easily.

This saves a few bytes in struct sec_pmic_dev due to member alignment.

Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://lore.kernel.org/r/20250409-s2mpg10-v4-18-d66d5f39b6bf@linaro.org


Signed-off-by: Lee Jones <lee@kernel.org>