thermal/drivers/thermal_mmio: Constify static struct thermal_mmio_ops

The only usage of thermal_mmio_ops is to pass its address to
devm_thermal_zone_of_sensor_register(), which has a pointer to const
struct thermal_zone_of_device_ops as argument. Make it const to allow
the compiler to put it in read-only memory.

Signed-off-by: Rikard Falkeborn <[e-mail]>
Acked-by: Talel Shenhar <[e-mail]>
Signed-off-by: Daniel Lezcano <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/thermal/thermal_mmio.c

···
 	return 0;
 }
 
-static struct thermal_zone_of_device_ops thermal_mmio_ops = {
+static const struct thermal_zone_of_device_ops thermal_mmio_ops = {
 	.get_temp = thermal_mmio_get_temperature,
 };