[media] si2157: revert si2157: Si2141/2151 tuner support

[media] si2157: revert si2157: Si2141/2151 tuner support

'Reset' loop does not look correct. I tested it very many times and
it never repeated those commands. If problem, it tries to solve,
really occurs on some situations better solution should be find out.

There is another patch which does not have such hackish looking loop.
Lets change to it.

Cc: Evgeny Plehov <EvgenyPlehov@ukr.net>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>