emulators/yuzu: unbreak with pkgconf after 72cb3d2eba79
CMake Error at externals/libusb/CMakeLists.txt:109 (add_library):
Cannot find source file: libusb/libusb/core.c Tried extensions .c .C .c++ .cc .cpp .cxx .cu .mpp .m .M .mm .h .hh .h++ .hm .hpp .hxx .in .txx .f .F .for .f77 .f90 .f95 .f03 .ispc
CMake Error at externals/libusb/CMakeLists.txt:109 (add_library):
No SOURCES given to target: usb
PR: 256912
Submitted by: jkim (based on)