The code to tell the lower layer to enable or disable watching for
certain things was lazy in disabling, it waited until a timer tick
to see if a disable was necessary.  Not a really big deal, but it
could be improved.

Modify the code to enable and disable watching immediately and don't
do it from the background timer any more.
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Tested-by: Kamlakant Patel <kamlakant.patel@cavium.com>