Add clock driver support for STM32MP21 SoCs.

Signed-off-by: Nicolas Le Bayon <nicolas.le.bayon@st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>

Add clock driver support for STM32MP25 SoCs.

Signed-off-by: Gabriel Fernandez <gabriel.fernandez@foss.st.com>
Signed-off-by: Valentin Caron <valentin.caron@foss.st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Cc: Lukasz Majewski <lukma@denx.de>
Cc: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>

STM32MP13 RCC driver uses Common Clock Framework and also a
'clk-stm32-core' API. Then STM32MPx RCC driver will contain only data
configuration (gates, mux, dividers and the way to check security)
or some specific clocks.
This API will be used by all new other generations of ST Socs.

Signed-off-by: Gabriel Fernandez <gabriel.fernandez@foss.st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Sean Anderson <seanga2@gmail.com>
Tested-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>

Add a directory in drivers/clk to regroup the clock drivers for all
STM32 Soc with CONFIG_ARCH_STM32 (MCUs with cortex M) or
CONFIG_ARCH_STM32MP (MPUs with cortex A).

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Reviewed-by: Grzegorz Szymaszek <gszymaszek@short.pl>
Acked-by: Sean Anderson <seanga2@gmail.com>
Change-Id: I955af307963f732167396f0157a30cf2fc91f150