[media] s5p-tv: Include missing platform_device.h header
[media] s5p-tv: Include missing platform_device.h header

Without this patch we get the following build error:
drivers/media/platform/s5p-tv/mixer_video.c:
In function ‘find_and_register_subdev’:
drivers/media/platform/s5p-tv/mixer_video.c:42:34: error:
‘platform_bus_type’ undeclared (first use in this function)

Signed-off-by: Sachin Kamat <1c3b1584a6008857f36c03c58f657c0fc16fc09e@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <ad86ba2154032c9f55743a190faa2459a9d61d42@redhat.com>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas