[PATCH] kbuild: Add better clang cross build support

Add cross target to CC if using clang. Also add custom gcc toolchain path for fallback gcc tools. COMPILER is previously set to "clang" if CC=clang was set from the make command line. So -target and -gcc-toolchain can be added to CC, since we already know that it is set. Clang will fallback to

[PATCH] kbuild: Add better clang cross build support

Add cross target to CC if using clang. Also add custom gcc toolchain path for fallback gcc tools. COMPILER is previously set to "clang" if CC=clang was set from the make command line. So -target and -gcc-toolchain can be added to CC, since we already know that it is set. Clang will fallback to