drivers: display: ili9xxx: convert to MIPI DBI API

Convert ili9xxx display drivers to use MIPI DBI API. Due to the fact
this change requires a new devicetree structure for the display driver
to build, required devicetree changes are also included in this commit
for all boards and shields defining an instance of an ili9xxx display.

Signed-off-by: Daniel DeGrasse <daniel.degrasse@nxp.com>