drivers/thermal/ti-soc-thermal: Add hwmon support

drivers/thermal/ti-soc-thermal: Add hwmon support

Expose ti-soc-thermal thermal sensors as HWMON devices.

  # sensors
  cpu_thermal-virtual-0
  Adapter: Virtual device
  temp1:        +54.2 C  (crit = +105.0 C)

  dspeve_thermal-virtual-0
  Adapter: Virtual device
  temp1:        +51.4 C  (crit = +105.0 C)

  gpu_thermal-virtual-0
  Adapter: Virtual device
  temp1:        +54.2 C  (crit = +105.0 C)

  iva_thermal-virtual-0
  Adapter: Virtual device
  temp1:        +54.6 C  (crit = +105.0 C)

  core_thermal-virtual-0
  Adapter: Virtual device
  temp1:        +52.6 C  (crit = +105.0 C)

Similar to imx_sc_thermal 0beb5dc39918e034f286701a3cbb4d98a8e26b52.

No need to take care of thermal_remove_hwmon_sysfs() since
devm_thermal_add_hwmon_sysfs() (a wrapper around devres) is
used. See 58995929be0877596f93649147647b4c465bceca.

Signed-off-by: Romain Naour <romain.naour@smile.fr>
Link: https://lore.kernel.org/r/20220218104725.2718904-1-romain.naour@smile.fr
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>