[media] tda18212: add support for ATSC and clearQAM on tda18272

tda18272 is programmed just like tda18212, but it also
supports ClearQAM and ATSC.

Add support for them. Tested with a Kworld UB435-Q on both
8VSB and 256QAM modes.

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>