thermal/drivers/sun8i: Free calibration nvmem after reading it

thermal/drivers/sun8i: Free calibration nvmem after reading it

The sun8i thermal driver reads calibration data via the nvmem API at
startup, updating the device configuration and not referencing the data
again.  Rather than explicitly freeing the nvmem data the driver relies
on devm_ to release it, even though the data is never referenced again.
The allocation is still tracked so it's not leaked but this is notable
when looking at the code and is a little wasteful so let's instead
explicitly free the nvmem after we're done with it.

Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20230719-thermal-sun8i-free-nvmem-v1-1-f553d5afef79@kernel.org