drm/amd/display: Fix pipe check condition for manual trigger

Condition for programming manually trigger used the wrong pipe (always
used top pipe instead of the one we are iterating through).

Fixes: 0baae624 ("drm/amd/display: Refactor fast update to use new HWSS build sequence")
Reviewed-by: Samson Tam <samson.tam@amd.com>
Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Alvin Lee <alvin.lee2@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>