kexec-tools: Add again the x32 patch

kexec-tools: Add again the x32 patch

kexec-tools upstream previously integrated the patch into master rev
587778e24c9 but for a bug report it was remove [1][2], after an intensive
testing on OpenSUSE 13.1 64 bits and in poky variants: qemux86 [3],
qemux86-64-x32 [4] and generix86-64 (minnow) [5] it worked.

I think that the upstream revert was due to some integration issue while
testing into OpenSUSE [2], i will try to push again to upstream.

[1] http://lists.infradead.org/pipermail/kexec/2015-March/013482.html
[2] https://github.com/horms/kexec-tools/commit/5041d45b1c6b66a0e6c48f6121c24cd9be506c68
[3] https://bugzilla.yoctoproject.org/show_bug.cgi?id=11050#c3
[4] https://bugzilla.yoctoproject.org/show_bug.cgi?id=11050#c4
[5] https://bugzilla.yoctoproject.org/show_bug.cgi?id=11050#c4

[YOCTO #11050]

Signed-off-by: Aníbal Limón <anibal.limon@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>