After writing data to flash space, next instruction is checking if flash
controller is busy writing to the flash memory. Memory barrier is required here
to avoid transaction re-ordering for data write and busy status check.
Signed-off-by: Vikas Manocha <vikas.manocha@st.com>
Same flash driver can be used by other stm32 families like stm32f7.
Better place for this driver would be mtd driver location.
Signed-off-by: Vikas Manocha <vikas.manocha@st.com>