soc: arm: st_stm32: common: Increase the value of HW semaphore retry

When running the blinky example on STM32H747, with the BOOT_CM4 bit set
to 0, the M4 core goes into panic.
Increasing the value of the hardware semaphore retry prevents this.

Signed-off-by: Guillaume Gautier <guillaume.gautier-ext@st.com>