clk: sunxi-ng: sun6i: Rename HDMI DDC clock to avoid name collision

[ Upstream commit 7f3ed79188f2f094d0ee366fa858857fb7f511ba ]

The HDMI DDC clock found in the CCU is the parent of the actual DDC
clock within the HDMI controller. That clock is also named "hdmi-ddc".

Rename the one in the CCU to "ddc". This makes more sense than renaming
the one in the HDMI controller to something else.

Fixes: c6e6c96d ("clk: sunxi-ng: Add A31/A31s clocks")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>