This silences the following compilation warning, presumably emitted
by llvm-ar in conjunction with Clang (Thin)LTO:
lib/nmi_backtrace.o: no symbols
This is a watchdog support library which is no-op on this
architecture, hence the empty object file, so let's avoid building
it entirely until a more aesthetically pleasing solution presents
itself.
Signed-off-by: Adam W. Willis <return.of.octobot@gmail.com>
Co-authored-by: Panchajanya1999 <panchajanya@azure-dev.live>