libusb build errors on arm64

[JeroMiya]

From user on support:

FAILED: : && /opt/android/ndk/toolchains/aarch64-linux-android-4.9/prebuilt/linux-x86_64/bin/aarch64-linux-android-g++ --sysroot=/opt/android/ndk/platforms/android-21/arch-arm64 -fexceptions -frtti -Wno-psabi -funwind-tables -llog -no-canonical-prefixes -fdata-sections -ffunction-sections -Wa,--noexecstack -fno-omit-frame-pointer -fno-strict-aliasing -O0 -g -DDEBUG -D_DEBUG -Wl,--no-undefined -Wl,-z,noexecstack -Wl,-z,relro -Wl,-z,now -Wl,-z,muldefs -Wl,--gc-sections -Wl,--build-id -Wl,-z,nocopyreloc -fPIE -pie apps/CMakeFiles/BasicServer.dir/BasicServer.cpp.o -o bin/BasicServer -L/opt/android/ndk/sources/crystax/empty -L/home/malcalde/Documents/Projects/osvr/OSVR-Android-Build/build/install/libs/arm64-v8a lib/libosvrServer.so lib/libosvrConnection.so lib/libosvrPluginHost.so /home/malcalde/Documents/Projects/osvr/OSVR-Android-Build/build/install/lib/libfunctionality.so -ldl lib/libosvrUtil.so /home/malcalde/Documents/Projects/osvr/OSVR-Android-Build/build/install/lib/libjsoncpp.so -Wl,-rpath-link,/home/malcalde/Documents/Projects/osvr/OSVR-Android-Build/build/src/OSVR-Core-prefix/src/OSVR-Core-build/lib "/opt/android/ndk/sources/cxx-stl/gnu-libstdc++/4.9/libs/arm64-v8a/libgnustl_shared.so" "/opt/android/ndk/sources/cxx-stl/gnu-libstdc++/4.9/libs/arm64-v8a/libsupc++.a" "/opt/android/ndk/sources/crystax/libs/arm64-v8a/libcrystax.so" -lc && : 
/opt/android/ndk/toolchains/aarch64-linux-android-4.9/prebuilt/linux-x86_64/bin/../lib/gcc/aarch64-linux-android/4.9/../../../../aarch64-linux-android/bin/ld: warning: libusb1.0.so, needed by lib/libosvrServer.so, not found (try using -rpath or -rpath-link) 
lib/libosvrConnection.so: undefined reference to `libusb_exit' 
lib/libosvrConnection.so: undefined reference to `libusb_open_device_with_vid_pid' 
lib/libosvrConnection.so: undefined reference to `libusb_claim_interface' 
lib/libosvrConnection.so: undefined reference to `libusb_close' 
lib/libosvrConnection.so: undefined reference to `libusb_init' 

Looks like libusb may be failing to build, or cmake is failing to find it once built, when targeting arm64.