With VPLL as source clock to FIMD,
Exynos DP Initializaton was failing sometimes with unstable clock.
Changing FIMD source to MPLL resolves this issue.
Signed-off-by: Ajay Kumar <ajaykumar.rs@samsung.com> Acked-by: Simon Glass <sjg@chromium.org> Acked-by: Donghwa Lee <dh09.lee@samsung.com> Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>