drivers: flash: stm32h7x: use max-erase-time instead of hard-coded timeout
drivers: flash: stm32h7x: use max-erase-time instead of hard-coded timeout

As the erase time for a sector differs by a few order of magnitude for the
various SoCs of the STM32H7 family, use the just added max-erase-time
property from the device tree instead of the hard-coded 4 seconds value.

Signed-off-by: Aurelien Jarno <bceb368e7f2cb351af47298f32034f0587bbe4a6@aurel32.net>

finikorg/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,galak/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr