clk: mediatek: mt8192: Drop flags for main/univpll fixed factors

clk: mediatek: mt8192: Drop flags for main/univpll fixed factors

The main/univpll clocks are used as clock sources for multiple
peripherals of different kind, some of which are critical (like AXIs);
a rate change on any of these two will produce a rate change on many
devices and that's likely to produce system instability if not done
correctly: this is the reason why we have (a lot of) "fixed factor"
main/univpll divider clocks, used by MUX clocks to provide different
rates based on PLL output dividers.

Following what was done on clk-mt8186-topckgen and also preventing the
same GPU DVFS issue, drop CLK_SET_RATE_PARENT from the aforementioned
clocks.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Link: https://lore.kernel.org/r/20221024102307.33722-8-angelogioacchino.delregno@collabora.com
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>