We need to look at hw.fb for the framebuffer, and add the translation
for the slave_plane_state. With these changes we set the correct
rectangle on the bigjoiner slave, and don't set incorrect
src/dst/visibility on the slave plane.

v2:
* Manual rebase (Manasi)

v3:
* hw.rotation instead of uapi.rotation (Ville)
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201117194718.11462-11-manasi.d.navare@intel.com