ARM: EXYNOS: add display driver for EXYNOS SoC

This patch is for display driver of EXYNOS SoC.

[1/5]: ARM: EXYNOS: definition of system registers
- to contorl FIMD of LBLK0 bypass selection, add missed definitions of system register
[2/5]: ARM: EXYNOS: add data structure for EXYNOS display driver
- It is needed to specific vidinfo_t data structure for EXYNOS display driver.
[3/5]: ARM: EXYNOS: add exynos lcd clock interface
- Is is newly defined to interface to get lcd source clock.
[4/5]: ARM: EXYNOS: support EXYNOS display driver
[5/5]: ARM: EXYNOS: add Makefile for exynos display driver

Thank you,
Donghwa Lee