media: v4l: fix uapi mpeg slice params definition

media: v4l: fix uapi mpeg slice params definition

We get a headers_check warning about the newly defined ioctl command
structures:

./usr/include/linux/v4l2-controls.h:1105: found __[us]{8,16,32,64} type without #include <linux/types.h>

This is resolved by including linux/types.h, as suggested by the
warning, but there is another problem: Three of the four structures
have an odd number of __u8 headers, but are aligned to 32 bit in the
v4l2_ctrl_mpeg2_slice_params, so we get an implicit padding byte
for each one. To solve that, let's add explicit padding that can
be set to zero and verified in the kernel.

Fixes: c27bb30e7b6d ("media: v4l: Add definitions for MPEG-2 slice format and metadata")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>