8192x8192 is the maximum supported resolution.

Signed-off-by: David Rosca <david.rosca@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Ruijing Dong <ruijing.dong@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 6e0d2fde)
Cc: stable@vger.kernel.org