Staging: Update TI-ST's TODO

Update the TODO of TI-ST to make sure it reflects current list
of activities that need to be done.
Also point it out to the user-space app code relevant to it.

Signed-off-by: Pavan Savoy <pavan_savoy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>