clk: stm32mp1: add CLK_SET_RATE_NO_REPARENT to Kernel clocks

clk: stm32mp1: add CLK_SET_RATE_NO_REPARENT to Kernel clocks

STM32MP1 clock IP offers lots of Kernel clocks that are shared
by multiple IP's at the same time.
Then boot loader applies a clock tree that allows to use all IP's
at same time and with the maximum of performance.
Not change parents on a change rate on kernel clocks ensures
the integrity of the system.

Signed-off-by: Gabriel Fernandez <gabriel.fernandez@st.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>