[media] s5p-fimc: Redefine platform data structure for fimc-is

Newer Exynos4 SoC are equipped with a local camera ISP that
controls external raw image sensor directly. Such sensors
can be connected through FIMC-LITEn (and MIPI-CSISn) IPs to
the ISP, which then feeds image data to the FIMCn IP. Thus
there can be two busses associated with an image source
(sensor). Rename struct s5p_fimc_isp_info describing external
image sensor (video decoder) to struct fimc_source_info to
avoid confusion. bus_type is split into fimc_bus_type and
sensor_bus_type. The bus type enumeration is extended to
include both FIMC Writeback input types.
The bus_type enumeration and the data structure name in the
board files are modified according to the above changes.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>