media: radio/wl128x: remove unnecessary (void*) conversions

The void * type pointer does not need to be cast.

Signed-off-by: Zhou jie <zhoujie@nfschina.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>