linux-yocto-tiny-kexecboot: revert Yocto specific console check

Revert Yocto-specific : "check console device file on fs when booting".
Fix kernel panic at boot because of the missing /dev/console.

Signed-off-by: Andrea Adami <andrea.adami@gmail.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>