media: vidtv: psi: add a Network Information Table (NIT)

Add a Network Information Table (NIT) as specified in ETSI EN 300 468.

This table conveys information relating to the physical organization of
the multiplexes carried via a given network and the characteristics of
the network itself.

It is conveyed in the output of vidtv as packets with TS PID of 0x0010

[mchehab+huawei@kernel.org: removed an extra blank line]
Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>