buildroot

gcc: drop gcc 4.5 specific code

We have removed gcc 4.5 support since a long time, so this commit
removes dead code that was only used when building a toolchain based
on gcc 4.5.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>