drm/amd/display: Add HUBP surface flip interrupt handler

On IGT, there is a test named amd_hotplug, and when the subtest basic is
executed on DCN31, we get the following error:

[drm] *ERROR* [CRTC:71:crtc-0] flip_done timed out
[drm] *ERROR* flip_done timed out
[drm] *ERROR* [CRTC:71:crtc-0] commit wait timed out
[drm] *ERROR* flip_done timed out
[drm] *ERROR* [CONNECTOR:88:DP-1] commit wait timed out
[drm] *ERROR* flip_done timed out
[drm] *ERROR* [PLANE:59:plane-3] commit wait timed out

After enable the page flip log with the below command:

echo -n 'format "[PFLIP]" +p' > /sys/kernel/debug/dynamic_debug/control

It is possible to see that the flip was submitted, but DC never replied
back, which generates time-out issues. This is an indication that the
HUBP surface flip is missing. This commit fixes this issue by adding
hubp1_set_flip_int to DCN31.

Reviewed-by: Nicholas Kazlauskas <[e-mail]>
Acked-by: Tom Chung <[e-mail]>
Signed-off-by: Rodrigo Siqueira <[e-mail]>
Tested-by: Daniel Wheeler <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hubp.c

···
 	.hubp_init = hubp3_init,
 	.set_unbounded_requesting = hubp31_set_unbounded_requesting,
 	.hubp_soft_reset = hubp31_soft_reset,
+	.hubp_set_flip_int = hubp1_set_flip_int,
 	.hubp_in_blank = hubp1_in_blank,
 	.program_extended_blank = hubp31_program_extended_blank,
 };