media: dvb-frontends/cxd2841er: update moddesc wrt new chip support

Since the driver now recognizes and supports more chip variants, reflect
this fact in the module description accordingly.

Signed-off-by: Daniel Scheller <d.scheller@gmx.net>
Acked-by: Abylay Ospan <aospan@netup.ru>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>