thermal: exynos: Support both EXYNOS4X12 SoCs

EXYNOS4212 and EXYNOS4412 have the same thermal block, so there is no
reason to include support only for EXYNOS4412 in this driver.

Cc: linux-pm@vger.kernel.org
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>