clk: sunxi-ng: h6-r: Use local parent references for CLK_FIXED_FACTOR

With the new clk parenting code and CLK_FIXED_FACTOR_{HW,FW_NAME}
macros, we can reference parents locally via pointers to struct clk_hw
or DT clock-names.

Convert existing CLK_FIXED_FACTOR definitions to either the _HW or
_FW_NAME variant based on whether the parent clock is internal or
external to the CCU.

Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>