media: vidtv: avoid copying data for PES structs

Minimize the number of data copies and initialization at
the code, passing them as pointers instead of duplicating
the data.

The only case where we're keeping the data copy is at
vidtv_pes_write_h(), as it needs a copy of the passed
arguments. On such case, we're being more explicit.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>