utimes: force to use 64-bit implementation if available and requested
Fixes 64-/32-bit time_t regression on ARM32 (reported for buildroot, see [1]
for details).
[1] https://gitlab.com/buildroot.org/buildroot/-/issues/128
Fixes: 48591e2a2 ("Provide fixups for riscv32.")
Signed-off-by: Peter Seiderer <ps.report@gmx.net>