thermal: ti-soc-thermal: Disable the CPU PM notifier for OMAP4430

It has been observed that on OMAP4430 (ES2.0, ES2.1 and ES2.3) the enabled
notifier causes errors on the DTEMP readout values:

ti-soc-thermal 4a002260.bandgap: in range ADC val: 52
ti-soc-thermal 4a002260.bandgap: in range ADC val: 64
ti-soc-thermal 4a002260.bandgap: in range ADC val: 64
ti-soc-thermal 4a002260.bandgap: out of range ADC val: 0
thermal thermal_zone0: failed to read out thermal zone (-5)
ti-soc-thermal 4a002260.bandgap: out of range ADC val: 0
thermal thermal_zone0: failed to read out thermal zone (-5)
ti-soc-thermal 4a002260.bandgap: out of range ADC val: 4
thermal thermal_zone0: failed to read out thermal zone (-5)
ti-soc-thermal 4a002260.bandgap: in range ADC val: 100

raw 100 translates to 133 Celsius on omap4-sdp, triggering shutdown due to
critical temperature.

When the notifier is disable for OMAP4430 the DTEMP values are stable:
ti-soc-thermal 4a002260.bandgap: in range ADC val: 56
ti-soc-thermal 4a002260.bandgap: in range ADC val: 56
ti-soc-thermal 4a002260.bandgap: in range ADC val: 57
ti-soc-thermal 4a002260.bandgap: in range ADC val: 57
ti-soc-thermal 4a002260.bandgap: in range ADC val: 56

Fixes: 5093402e ("thermal: ti-soc-thermal: Enable addition power management")
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Acked-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20201029100335.27665-1-peter.ujfalusi@ti.com