gcc-4.5: Fix cross-gcc build for 64 bit targets

Building gcc-cross-intermediate for x86_64
failed since the notion of multlib has changed
in oe-core. So we needed to sync 64bit hack
patch from oe-core/gcc-4.6 into meta-oe 4.5

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>