drm/amd/display: refine wake up aux in retrieve link caps

[Why]
Read set_power_state dpcd after HPD cause USB4 CTS 4.2.1.1

[How]
Read LTTPR caps first. If aux channel not ready, wake up aux channel.
If wake up aux channel return pass, retrieve lttpr caps again. If wake
up aux channel return false, register a detection retry timer.

Tested-by: Mark Broadworth <mark.broadworth@amd.com>
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Lewis Huang <Lewis.Huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>