thermal/drivers/exynos: Drop id field

We do not use the value, and only Exynos 7 defines this alias anyway.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Mateusz Majewski <m.majewski2@samsung.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20231201095625.301884-3-m.majewski2@samsung.com