ivi-shell: rename ivi_controller_interface

ivi-shell: rename ivi_controller_interface

The name of ivi_controller_interface is changed to ivi_layout_interface
with this patch.

This name is better suited to the interface, because it is implemented
in ivi-layout.c and its methods are linked to ivi_layout* functions.

Furthermore, the controller modules (e.g. hmi-controller) are the users
of this interface and they have their own interfaces,
which are called *_controller_interface,
e.g.: ivi_hmi_controller_interface.

This causes confusion about the software architecture.

Signed-off-by: Emre Ucan <eucan@de.adit-jv.com>
Tested-by: Nobuhiko Tanibata <NOBUHIKO_TANIBATA@xddp.denso.co.jp>
Reviewed-by: Nobuhiko Tanibata <NOBUHIKO_TANIBATA@xddp.denso.co.jp>