common/rc: add default _udev_wait timeout

common/rc: add default _udev_wait timeout

If udevd isn't running then "udevadm wait" loops endlessly. With a
--timeout parameter provided, udevadm (udev-254.27) prints to stderr:
  Timed out for waiting devices being initialized.

The error message causes test failure via golden output mismatch and
is easier to debug than an infinite loop.

The timeout parameter is also compatible with existing
args="--removed <dev>" callers. 60 seconds is relatively arbitrary, but
should be long enough to avoid premature timeout on regular systems.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Zorro Lang <zlang@kernel.org>
Signed-off-by: Zorro Lang <zlang@kernel.org>