media: dvb: Fix typos in comments across various files

This patch corrects spelling errors in comments within
the media/dvb-frontends directory found by codespell to enhance
clarity and maintainability of the code.
This change does not affect the functionality.

Signed-off-by: Yu Jiaoliang <yujiaoliang@vivo.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>