media: vidtv: Add a music instead of playing a single tone

Keep playing a single tone is not too nice, and prevents
checking some weird things.

So, instead, implement a simple tone generator, changing
the code to play a public domain song (5th Symphony of
Beethoven), using sinusoidal waves.

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