Place the flash_stm32_sem_take and flash_stm32_sem_give
function to header file for common to use in any flash driver

Signed-off-by: Francois Ramu <[email protected]>

Move the stm32 flash driver ex_op functions to common
flash_stm32_ex_op.c file.

Signed-off-by: Francois Ramu <[email protected]>

Implement the readout protection for the STM32H7 series.
Define the specific functions used by the flash_stm32h7.
Remove reference to the stm32H7 from the flash_stm32.c

Signed-off-by: Francois Ramu <[email protected]>

Move the stm32h7 flash register manipulation in a write_optb()
to be called by the flash_stm32_set_rdp_level

Signed-off-by: Francois Ramu <[email protected]>

Add the configuration to run the testcase
with READOUT_PROTECTION (RDP) on stm32h7 disco kits

Signed-off-by: Francois Ramu <[email protected]>

Move the flash_stm32_write_protection and
flash_stm32_option_bytes_lock functions to a common
file for stm32 devices including stm32h7

Signed-off-by: Francois Ramu <[email protected]>