arm: tegra: fb: Add support for up-down rotation

Use the flipping feature to allow rotating the display 180°.

Change-Id: I524a7242d2d2b7ae71035b45a52f2d4491d28d87
Signed-off-by: Alban Bedel <alban.bedel@avionic-design.de>
Reviewed-on: http://review.adnet.avionic-design.de/2074
Reviewed-by: Dirk Leber <dirk.leber@avionic-design.de>