thermal/drivers/mediatek/lvts_thermal: Honor sensors in immediate mode

Each controller can be configured to operate on immediate or filtered
mode. On filtered mode, the sensors are enabled by setting the
corresponding bits in MONCTL0, while on immediate mode, by setting
MSRCTL1.

Previously, the code would set MSRCTL1 for all four sensors when
configured to immediate mode, but given that the controller might not
have all four sensors connected, this would cause interrupts to trigger
for non-existent sensors. Fix this by handling the MSRCTL1 register
analogously to the MONCTL0: only enable the sensors that were declared.

Fixes: f5f633b1 ("thermal/drivers/mediatek: Add the Low Voltage Thermal Sensor driver")
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20230706153823.201943-3-nfraprado@collabora.com