MLK-13929-1 video: Add MIPI DSI host controller driver for i.MX7ULP

MLK-13929-1 video: Add MIPI DSI host controller driver for i.MX7ULP

Add the host driver base from kernel for MIPI DSI controller on i.MX7ULP.
The controller provides a DPI-2 interface for LCDIF video stream, and a APB interface
for packet transmission.

The driver provides APIs to register a MIPI panel device and its driver. The panel
driver can use the write packet function provided by the host driver to send control
packets to panel device via APB interface.

MIPI DSI has its PHY and dedicated PLL. The driver will setup them when enabling the DSI
host.

Signed-off-by: Ye Li <ye.li@nxp.com>
(cherry picked from commit e02115dd1c5d36ec06eabcb5a0b8e09aaf0f29a0)