drm/radeon: fix amd afusion gpu setup aka sumo v2

commit bd25f0783dc3fb72e1e2779c2b99b2d34b67fa8a upstream.

Set the proper number of tile pipe that should be a multiple of
pipe depending on the number of se engine.

Fix:
https://bugs.freedesktop.org/show_bug.cgi?id=56405
https://bugs.freedesktop.org/show_bug.cgi?id=56720

v2: Don't change sumo2

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
[bwh: Backported to 3.2: don't define/use *_GB_ADDR_CONFIG_GOLDEN]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>