[media] s5p-fimc: Add pipeline ops to separate FIMC-LITE module

In order to reuse the FIMC-LITE module on Exynos4 and Exynos5
SoC introduce a set of callbacks for the media pipeline control
from within FIMC/FIMC-LITE video node. It lets us avoid symbol
dependencies between FIMC-LITE and the whole media device driver,
which simplifies the initialization sequences and doesn't
introduce issues preventing common kernel image for exynos4 and
exynos5 SoCs.
This patch also corrects following build errors:
drivers/built-in.o: In function `buffer_queue':
drivers/media/video/s5p-fimc/fimc-lite.c:414: undefined reference
to `fimc_pipeline_s_stream'
drivers/built-in.o: In function `fimc_lite_resume':
drivers/media/video/s5p-fimc/fimc-lite.c:1518: undefined reference
to `fimc_pipeline_initialize'
drivers/built-in.o: In function `fimc_lite_suspend':
drivers/media/video/s5p-fimc/fimc-lite.c:1544: undefined reference
to `fimc_pipeline_shutdown'
when only CONFIG_VIDEO_EXYNOS_FIMC_LITE is selected, without
CONFIG_VIDEO_S5P_FIMC.

Reported-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>