dtoverlays: Add overlays for JDI LT070ME05000 1200x1920 DSI panel

dtoverlays: Add overlays for JDI LT070ME05000 1200x1920 DSI panel

Credit to forum member gizmomouse on
https://www.raspberrypi.org/forums/viewtopic.php?f=98&t=253912 and
Andrey Vostrukhin of Harlab for these overlays.

See https://github.com/harlab/CM4_LCD_LT070ME05000 for
schematics and docs for the adapter board to connect this panel which
is found in the Asus/Google 2013 Nexus 7" tablet and therefore
relatively easily available.

Note that this uses 4 DSI data lanes, and therefore MUST be used
with DISP1 on a Compute Module. It can not be used on a standard
Pi.

There are two versions of the adapter board. V1 connects the
display controls to Pi GPIOs, whilst v2 uses an I2C GPIO expander
so needs no additional connections beyond the FFC and power.

The touchscreen overlay for these panels varies, so that part
is not configured.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>