Without the data-mapping devicetree property my display won't
work properly. It is flickering, because the bus flags won't
be assigned without a defined bus format by the imx parallel
display driver. There was a discussion about the removal [1]
and an agreement that a better solution is needed, but it is
missing so far. 

Obviously bus format in panel-dpi is broken, so this revert 
looks necessary. The current state of panel-dpi isn't consistent 
with changes introduced in commit 4a1d0dbc8332231d1d500d7a1d13c45457262a97

So what would be the better approach?

Another approach is using panel instead of panel-dpi.

[1] https://patchwork.freedesktop.org/patch/357659/?series=74705&rev=1

This reverts commit d021d751c14752a0266865700f6f212fab40a18c.

But, also you need to revert 99f155d0776fb8838e326efce056aa08e25433d0

Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>

Tested-by: Denys Drozdov <denys.drozdov@toradex.com>