EXYNOS: support EXYNOS MIPI DSI interface driver.

EXYNOS: support EXYNOS MIPI DSI interface driver.

EXYNOS SoC platform has MIPI-DSI controller and MIPI-DSI
based LCD Panel could be used with it. This patch supports MIPI-DSI driver
based Samsung SoC chip.

LCD panel driver based MIPI-DSI should be registered to MIPI-DSI driver at
board file and LCD panel driver specific function registered to mipi_dsim_ddi
structure at lcd panel init function called system init.
In the MIPI-DSI driver, find lcd panel driver by using registered
lcd panel name, and then initialize lcd panel driver.

Signed-off-by: Donghwa Lee <dh09.lee@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Acked-by: Anatolij Gustschin <agust@denx.de>