boot: zephyr: Configure mimxrt685_evk board
boot: zephyr: Configure mimxrt685_evk board

The mimxrt685_evk board has large slots so we need to increase
CONFIG_BOOT_MAX_IMG_SECTORS from the default.

Signed-off-by: Maureen Helm <87a696db5547fa477bda9f9e0f00013c839c14d3@nxp.com>

ATmobica/mcuboot,ATmobica/mcuboot,runtimeco/mcuboot,ATmobica/mcuboot,runtimeco/mcuboot,runtimeco/mcuboot,ATmobica/mcuboot,runtimeco/mcuboot,ATmobica/mcuboot,runtimeco/mcuboot