boards: arm: lpcxpresso55s69: Fix flash/ram sizes for non-secure
boards: arm: lpcxpresso55s69: Fix flash/ram sizes for non-secure

Fix the settings in lpcxpresso55s69_ns.yaml to reflect the normal amount
of flash/ram that is allocated to the non-secure side.

Signed-off-by: Kumar Gala <a5e5248af4cd4f0ed8c515f61d40a6e2db46a66e@linaro.org>

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