Support for console on meson

configname: CONFIG_SERIAL_MESON_CONSOLE

Linux Kernel Configuration
└─>Device Drivers
└─>Character devices
└─>Serial drivers
└─>Support for console on meson
In linux kernel since version 3.18 (release Date: 2014-12-07)  
Say Y here if you wish to use a Amlogic MesonX UART as the
system console (the system console is the device which
receives all kernel messages and warnings and which allows
logins in single user mode) as /dev/ttyAMLx.