Add support for C-M4 core on STM32H7 series.
It is enabled in Dual core context with 2 alternatives boot methods:
* Boot CM4 CM7: Both core boot at reset, then CM4 enters Stop mode.
CM7 performs system configuration then finally wakes up CM4
* Boot CM7, CM4 Gated: Only CM7 boots at reset. Once done with
system configuration it triggers (requires option byte update)
Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>
Provide basic clock control driver for STM32H7.
Bus clock activation is done through CM7 and CM4 common registers
so we don't have to care to the CPU Id before accessing.
Accesses are not protected for now. Only possible configuration
is system clock source set to HSE driven PLL.
Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>
Erwan Gouriou