Integrate yocto-install/clean-boot-if-no-logo

Commit: seco-ne/tools/yocto-install@ff730343

prepare-logo.sh: clean boot directory and boot script if logo file was not found

This is a fix for issue [746-001643] bootlogo improvements.

If original logo file won`t be found in boot directory, command line to load logo will be removed from boot script. logo.dat will also be removed from boot directory.

Also add the '-o' parameter for "load" command, so a missing logo does not make the boot fail.

Signed-off-by: Dmitry Petrov dmitry.petrov@rtsoft.de