kexec/ppc64 ELF ABIv2 ABI support

When building in PPC64 little endian mode, the compiler is now using the
new ABI v2. Among other changes, this new ABI removes the function
descriptors and changes the way the TOC address is computed when entering a
C function.

The purgatory assembly part where the dot symbols are removed, and ELF
relocation code are impacted in this patch.

Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
mlpost: http://lists.infradead.org/pipermail/kexec/2014-January/010935.html
kexec/ppc64 fix device tree endianess issues for memory attributes

All the attributes exposed in the device tree are in Big Endian format.

This patch add the byte swap operation for some entries which were not yet
processed, including those fixed by the following kernel's patch :

https://lists.ozlabs.org/pipermail/linuxppc-dev/2014-January/114720.html

To work on PPC64 Little Endian mode, kexec now requires that the kernel's
patch mentioned above is applied on the kexecing kernel.

Tested on ppc64 LPAR (kexec/dump) and ppc64le in a Qemu/KVM guest (kexec)

Changes from v1 :
 * add processing of the following entries :
   - ibm,dynamic-reconfiguration-memory
   - chosen/linux,kernel-end
   - chosen/linux,crashkernel-base & size
   - chosen/linux,memory-limit
   - chosen/linux,htab-base & size
   - linux,tce-base & size
   - memory@/reg
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
mlpost: http://lists.infradead.org/pipermail/kexec/2014-January/010999.html