pico-imx7d: Provide a way to escape the Falcon mode
When CONFIG_SPL_OS_BOOT is selected, it is still convenient to be able
to escape from Falcon mode and boot to U-Boot proper.
Add a mechanism that allows booting in U-Boot proper when the
key 'c' is entered on console at boot time.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>