galaxys2: add AdvancedDisplay

This partially reverts commit 99d12c6a903a3199ba4956add53b82837d90ca9c,
we want to reuse some of it. The implementation appears to be fully
compatible with smdk4412's, so let's make this a common thing at
some point

Change-Id: I080484ad010f881a22a4486a6c082d0fbc17a529