Change to use autotools.eclass

Recently I have bought a cubieboard2 for my work, and I use your overlay for needed programs. But I've found some things, that I want to change.
I want to add different kernel source directly from linux-sunxi/linux-sunxi repo
And the way sunxi-mali is installed and handles eselect thingie.
I will submit those commits later, and for now I want to submit minor cosmetic changes to your new libump ebuild.