The recent build failures on various platforms were apparently caused by
the fact that LTO build support in the configure script does not check
if it has a suitable version of gcc and simply assumes that gcc-ar is
available and can be used for intermediate files.
Since we really don't need to build nasm with LTO, simply disable it and
keep the whole build more portable
Signed-off-by: Felix Fietkau <nbd@nbd.name>