video: stm32: remove the compatible "synopsys, dw-mipi-dsi" support

video: stm32: remove the compatible "synopsys, dw-mipi-dsi" support

Remove the compatible "synopsys,dw-mipi-dsi" added in U-Boot
(it don't exist in Linux kernel binding); it is only used
to bind the generic synopsys UCLASS_DSI_HOST "dw_mipi_dsi" to
the driver "stm32-display-dsi" UCLASS_VIDEO_BRIDGE

This binding is done in Linux kernel drivers without compatible
(dw_mipi_dsi_bind() is called in bind of driver, for example in
drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c).

This patch does the same in U-Boot driver, the STM32 driver
calls during its bind the function device_bind_driver_to_node
to bind the generic driver "dw_mipi_dsi" at the same address.

This patch reduces the device tree differences
between Linux kernel and U-Boot for stm32mp1 platform.

Tested with v2020.01-rc1 on STM32MP157C-EV1 and STM32MP157C-DK2.

The dependency of driver is clearer and the probe order is guaranteed.

STM32MP> dm tree
 Class     Index  Probed  Driver                Name
-----------------------------------------------------------
 root          0  [ + ]   root_driver           root_driver
 sysreset      0  [   ]   syscon_reboot         |-- reboot
 simple_bus    0  [ + ]   generic_simple_bus    |-- soc
 serial        0  [ + ]   serial_stm32          |   |-- serial@40010000
...
 video_brid    0  [ + ]   stm32-display-dsi     |   |-- dsi@5a000000
 dsi_host      0  [ + ]   dw_mipi_dsi           |   |   |-- dsihost
 panel         0  [ + ]   rm68200_panel         |   |   `-- panel-dsi@0
...

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>