drm/bridge: analogix_dp: Properly disable aux chan retries on rockchip

The comments in analogix_dp_init_aux() claim that we're disabling aux
channel retries, but then right below it for Rockchip it sets them to
3.  If we actually need 3 retries for Rockchip then we could adjust
the comment, but it seems more likely that we want the same retry
behavior across all platforms.

Cc: Stéphane Marchesin <marcheu@chromium.org>
Cc: 征增 王 <wzz@rock-chips.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180423105003.9004-21-enric.balletbo@collabora.com