thermal: exynos: Fix to set the second point correction value

This patch sets the second point trimming value according to the platform
data if the register value is 0.

Acked-by: Jonghwa Lee <jonghwa3.lee@samsung.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Acked-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>