drm/radeon/kms: move mtrr range add and memory information

Move mtrr range and memory information printing to radeon_object_init,
this are memory information and initialization common to all GPU and
they better fit in this function. Will also prevent code duplication
with upcoming init path changes.

airlied: fixed warning introduced

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>