drivers/sensor: ms5607: fix compensation for temperature < 20C
drivers/sensor: ms5607: fix compensation for temperature < 20C

When the temperature is lower than 20C, adc_temperature is smaller than
(data->t_ref << 8), which should yield a negative value for dT. While dT
and adc_temperature are correctly declared as signed, the subtrahend is
wrongly casted to unsigned, yielding insanely high temperature values.
Fix that by casting it to int32_t instead of uint32_t.

Signed-off-by: Aurelien Jarno <bceb368e7f2cb351af47298f32034f0587bbe4a6@aurel32.net>

finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,galak/zephyr,galak/zephyr,galak/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr