This reverts commit cf01c743a8.
Adding an unexplained delay seemed wrong in the first place, but it fixed
the display on the MCB2388.
Turns out the display was erroneously operating in 8-bit mode due to the
uninitialized flag register.
Why the delay helped here I don't know.
But with #12634 fixing this, this hack is not needed anymore.
The driver can only be used with either 4 or 8 bit modes. Checking if the 5th pin is set in the configuration is enough the determine if 8bit mode should be used or not