Fix SD card image creation script
Fix SD card image creation script

For some set of ext4 filesystem sizes, SD card image was not generated
correctly. This patch fixes it by reusing different approach of calculating
partition start/end. This is based on implementation from RaspberryPi yocto
repository:

http://git.yoctoproject.org/cgit/cgit.cgi/meta-raspberrypi/

Signed-off-by: Guillaume Tucker <e7e20b7c30f19d4ca6b81319ef81bf200369d137@arm.com>

nezticle/meta-mali,ARM-software/meta-mali,ARM-software/meta-mali,ARM-software/meta-mali,nezticle/meta-mali,nezticle/meta-mali