misc: ad525x_dpot: use driver core groups for sysfs files

In the Linux kernel, the following vulnerability has been resolved: misc: ad525x_dpot: use driver core groups for sysfs files ad_dpot_probe() creates per-RDAC sysfs files manually and then optionally creates the command sysfs group. This leaves probe responsible for rolling back partial sysfs state and makes remove responsible for matching every file that probe created. Move the device attributes into driver core dev_groups for the I2C and SPI drivers and use an is_visible() callback to expose only the attributes supported by the probed device. With this shape, the driver core creates the sysfs files only after probe succeeds and removes them before the remove callback frees the driver data.