ARM: dts: add fimd device support for exynos3250-rinato

This patch adds fimd device node which is a display controller
for Exynos3250 Rinato board.

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene@kernel.org>