Fix time for old 32bit systems

Fix time for old 32bit systems

The fix introduced in fe47ecb5504a ("Fix time for 32bit systems again")
made the incorrect assumption, that the macro _TIME_BITS=64 was always
available. It seems like that this is not the case for old systems,
causing 32bit builds to break there.

Lets completely rework 32bit time support, by actually detecting the
hosts size for the time.

This will break cross-compilation, as the configure script is run on the
host, but since we do not seem to support cross-builds anyway (all archs
are build on emulated or native targets), this should be acceptable.

Fixes fe47ecb5504a ("Fix time for 32bit systems again")

Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>