This commit updates libusb to version 1.0.20, and adds a patch that
should fix parallel make issues particular to this version and probably
fixed in the next version.
This commit also moves to using Github as the source for libusb.
Signed-off-by: Jeroen Roovers <jer@airfi.aero>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
