dt-bindings: clock: stm32mp1 new compatible for secure rcc

Introduce new compatible string "st,stm32mp1-rcc-secure" for
stm32mp1 clock driver when the device is configured with RCC
security support hardened.

Signed-off-by: Etienne Carriere <etienne.carriere@foss.st.com>
Signed-off-by: Gabriel Fernandez <gabriel.fernandez@foss.st.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210617051814.12018-11-gabriel.fernandez@foss.st.com


Signed-off-by: Stephen Boyd <sboyd@kernel.org>