drm/radeon: fix page directory update size estimation
drm/radeon: fix page directory update size estimation

Take padding into account as well.

Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=75651

Signed-off-by: Christian König <c7ea837d7a46effe4232b086213468b8b31643bf@amd.com>
Reviewed-by: Alex Deucher <08dc22c6156113f2deff178e35e3ed9b24d6af9e@amd.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs