drm/exynos: vidi: add component support

This patch adds component support for vidi driver.

vidi driver is a kms driver so it doesn't need to be registered
to exynos_drm_subdrv_list. For this, it changes for the component
framework to be used for vidi driver.

This patch fixes below error also,

# echo 1 > /sys/devices/platform/exynos-drm-vidi/connection
[   55.618529] ------------[ cut here ]------------
[   55.621960] WARNING: CPU: 0 PID: 1397 at drivers/gpu/drm/drm_irq.c:1203 exynos_drm_crtc_dpms+0x88/0x17c()
[   55.631268] Modules linked in:
[   55.634278] CPU: 0 PID: 1397 Comm: sh Not tainted 3.18.0-rc2-146253-g31449d7 #1154
[   55.641885] [<c0014400>] (unwind_backtrace) from [<c0011570>] (show_stack+0x10/0x14)
[   55.649597] [<c0011570>] (show_stack) from [<c04764f4>] (dump_stack+0x84/0xc4)
[   55.656802] [<c04764f4>] (dump_stack) from [<c00218b8>] (warn_slowpath_common+0x6c/0x88)
[   55.664866] [<c00218b8>] (warn_slowpath_common) from [<c0021970>] (warn_slowpath_null+0x1c/0x24)
[   55.673632] [<c0021970>] (warn_slowpath_null) from [<c027a780>] (exynos_drm_crtc_dpms+0x88/0x17c)
[   55.682482] [<c027a780>] (exynos_drm_crtc_dpms) from [<c027a910>] (exynos_drm_crtc_commit+0x14/0x44)
[   55.691622] [<c027a910>] (exynos_drm_crtc_commit) from [<c025521c>] (drm_crtc_helper_set_mode+0x3d0/0x51c)
[   55.701233] [<c025521c>] (drm_crtc_helper_set_mode) from [<c0255d68>] (drm_crtc_helper_set_config+0x87c/0x9dc)
[   55.711230] [<c0255d68>] (drm_crtc_helper_set_config) from [<c026afa8>] (drm_mode_set_config_internal+0x58/0xd4)
[   55.721380] [<c026afa8>] (drm_mode_set_config_internal) from [<c025c208>] (restore_fbdev_mode+0xcc/0xec)
[   55.730834] [<c025c208>] (restore_fbdev_mode) from [<c025c244>] (drm_fb_helper_restore_fbdev_mode_unlocked+0x1c/0x30)
[   55.741424] [<c025c244>] (drm_fb_helper_restore_fbdev_mode_unlocked) from [<c025e0a8>] (drm_fb_helper_set_par+0x1c/0x60)
[   55.752271] [<c025e0a8>] (drm_fb_helper_set_par) from [<c025e174>] (drm_fb_helper_hotplug_event+0x88/0xc4)
[   55.761906] [<c025e174>] (drm_fb_helper_hotplug_event) from [<c02571c4>] (drm_helper_hpd_irq_event+0xc8/0x134)
[   55.771898] [<c02571c4>] (drm_helper_hpd_irq_event) from [<c028e27c>] (vidi_store_connection+0x90/0xc8)
[   55.781268] [<c028e27c>] (vidi_store_connection) from [<c0125f80>] (kernfs_fop_write+0xc0/0x180)
[   55.790045] [<c0125f80>] (kernfs_fop_write) from [<c00cdf60>] (vfs_write+0xa0/0x1ac)
[   55.797757] [<c00cdf60>] (vfs_write) from [<c00ce468>] (SyS_write+0x44/0x9c)
[   55.804790] [<c00ce468>] (SyS_write) from [<c000e6a0>] (ret_fast_syscall+0x0/0x30)
[   55.812328] ---[ end trace 3c0fe4386702d4dd ]---

This issue occurs when modeset to vidi is tried in case that drm_vblank_init
is called prior to crtc creation of vidi driver. In this case, crtc number
of vidi is invalid so any requests with the crtc number will fail.
This patch guarantees drm_vblank_init to be called after all kms drivers
are ready by using component framework.

Signed-off-by: Inki Dae <inki.dae@samsung.com>