drm/sun4i: dw-hdmi: Fix max. frequency for H6

stable inclusion
from stable-5.10.17
commit 664b66e3552c219b7591e772d608160911401288
bugzilla: 48169

--------------------------------

[ Upstream commit 1926a050 ]

It turns out that reasoning for lowering max. supported frequency is
wrong. Scrambling works just fine. Several now fixed bugs prevented
proper functioning, even with rates lower than 340 MHz. Issues were just
more pronounced with higher frequencies.

Fix that by allowing max. supported frequency in HW and fix the comment.

Fixes: cd906375 ("drm/sun4i: DW HDMI: Lower max. supported rate for H6")
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Tested-by: Andre Heider <a.heider@gmail.com>
Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20210209175900.7092-6-jernej.skrabec@siol.net


Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>