Move the GEM's size and address cells properties to the common
dtsi file.

Cc: Andreas Färber <afaerber@suse.de>
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: NAndreas Färber <afaerber@suse.de>
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>