thermal/drivers/mediatek/lvts: Disable low offset IRQ for minimum threshold

In order to get working interrupts, a low offset value needs to be
configured. The minimum value for it is 20 Celsius, which is what is
configured when there's no lower thermal trip (ie the thermal core
passes -INT_MAX as low trip temperature). However, when the temperature
gets that low and fluctuates around that value it causes an interrupt
storm.

Prevent that interrupt storm by not enabling the low offset interrupt if
the low threshold is the minimum one.

Cc: stable@vger.kernel.org
Fixes: 77354eae ("thermal/drivers/mediatek/lvts_thermal: Don't leave threshold zeroed")
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Link: https://lore.kernel.org/r/20250113-mt8192-lvts-filtered-suspend-fix-v2-3-07a25200c7c6@collabora.com


Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>