ARM: EXYNOS4: Change devname for FIMD clkdev

According to SoC name, EXYNOS4, this patch changes devname
for FIMD from 's5pv310-fb' to 'exynos4-fb'.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
[kgene.kim@samsung.com: removed to change wrong clock name]
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>