staging: ti-soc-thermal: fix condition to apply hyst

While updating talert thresholds, threshold cold must
always be lower than threshold hot. This patch fixes
the function ti_bandgap_update_alert_threshold to only
change the thresholds by applying a hysteresis when
they violate this condition.

Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>