Fix util-linux build on MIPS

As reported in bug #635, util-linux doesn't build due to missing
constant definitions related to the a.out binary format. We fix this
by hardcoding these constant definitions, as done in newer versions of
util-linux.

Obviously, the long term fix is to upgrade to util-linux-ng, but this
is probably not acceptable for 2010.08.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>