staging: drm/omap: invert dimensions on crtc when rotated

If rotated 90 or 270, we need to invert the dimensions used by drm
core for calculating if the dimensions of an attached fb are correct.

Signed-off-by: Rob Clark <rob@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>