thermal: ti-soc-thermal: Remove CPU_THERMAL Dependency from TI_THERMAL

Currently when CPU_THERMAL is not defined the thermal sensors
are not even exposed consequently no cooling is possible. CPU_THERMAL
eventually depends on CPUFREQ. CPPUFREQ is not the only cooling
for CPU.

The thermal shutdown for critical temperatures is another
cooling solution which will currently not get enabled if CPU_THERMAL
is not defined. Remove this dependency so as to have the last level
of thermal protection working even without CPUFREQ defined.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>