Boot: Zephyr: Boards: Fix STM32H750B-DK App in Ext Flash support#2479

JarmouniA wants to merge 2 commits intomcu-tools:mainmcu-tools/mcuboot:mainfrom

JarmouniA:fix_h750b-dk_ext-flash-appJarmouniA/mcuboot_dev:fix_h750b-dk_ext-flash-appCopy head branch name to clipboard