drm/amd/display: Use a reasonable timeout for framebuffer fence waits

Patch '5edb0c9b Fix deadlock with display during hanged ring recovery'
was accidentaly removed during one of DALs code merges.

Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>