drivers/thermal/exynos_thermal.c: use devm_* functions

drivers/thermal/exynos_thermal.c: use devm_* functions

devm_* functions are used to replace kzalloc, request_mem_region, ioremap
and request_irq functions in probe call.  With the usage of devm_*
functions explicit freeing and unmapping is not required.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Sachin Kamat <sachin.kamat@samsung.com>
Cc: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: Len Brown <lenb@kernel.org>
Cc: "Brown, Len" <len.brown@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>