Removes nosuid form the fstab file

Ubuntu Touch uses suid executables, in order to make it work it is
necessary to remove the nosuid entry from the fstab file.

Signed-off-by: Felipe Zimmerle <felipe@zimmerle.org>
Modifies the permission of the brightness control file

This is needed to make Ubuntu able to change the the brightness
of the screen.

Signed-off-by: Felipe Zimmerle <felipe@zimmerle.org>