powerpc: disable binutils 2.24 for little endian

Binutils 2.24 produces broken code when compiling the kernel for
ppc64le, so prevent this combination. See:

https://sourceware.org/ml/binutils/2013-12/msg00200.html



The problem manifests early in the boot process with "Kernel access of
bad area, sig: 11" in arch_match_cpu_phys_id().

The fix has been merged upstream as commit
57fa7b8c7e59e35bced580f9bcb9668af43fdbce, which is available since
Binutils 2.25.

Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>