scripts/coccinelle: add conversion of integers to timeout values

Some legacy code still passes integer literals in milliseconds as the
value to functions that take a timeout.  This usage interferes with
plans to replace the millisecond representation with a more generic
k_timeout_t value.  Add a Coccinelle script to convert call sites to
use the proper constants and macros.

Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>