staging: media: Remove unused function atomisp_set_stop_timeout()

The function atomisp_set_stop_timeout on being called, simply returns
back. The function hasn't been mentioned in the TODO and doesn't have
FIXME code around. Hence, atomisp_set_stop_timeout and its calls have been
removed.

This was done using Coccinelle.

@@
identifier f;
@@

void f(...) {

-return;

}

Signed-off-by: simran singhal <singhalsimran0@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>