clk: meson: g12a: fix cpu clock rate setting

CLK_SET_RATE_NO_REPARENT is wrongly set on the g12a cpu premux0 clocks
flags, and CLK_SET_RATE_PARENT is required for the g12a cpu premux0 clock
and the g12b cpub premux0 clock, otherwise CCF always selects the SYS_PLL
clock to feed the cpu cluster.

Fixes: ffae8475 ("clk: meson: g12a: add notifiers to handle cpu clock change")
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>