Revert "serial: sh-sci: Add device tree support for r8a7779"

This reverts commit fcbee4d4.

It wasn't quite ready to go in yet, sorry about that.

Cc: Simon Horman <horms@verge.net.au>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>