drm/amd/display: Do not count I2C DEFERs with AUX DEFERs

[WHY]
DP 2.0 SCR specifies that
"A DPTX shall distinguish I2C_DEFER|AUX_ACK from AUX_DEFER. AUX retries
due to
I2C_DEFER are not counted as part of minimum 7 retires (sic) upon
AUX_DEFER’s"

Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>