kexec-tools: bump version from v2.0.4 to v2.0.9.

kexec-tools: bump version from v2.0.4 to v2.0.9.

- kexec-tools is now distributed with tarballs of .tar.gz and .tar.xz
   format; .tar.bz2 are not provided anymore.
 - Add CONFIG_KEXEC_LZMA for selecting lzma support.

Patches are updated along to:

 - Remove the now unnecessary patch 0004-mips_regdefs.patch.
 - Drop 100-reduce_size.patch because the size reduction is marginal.
 - Allow zlib and lzma support coexist together.  This patch has been
   merged into upstream project.
 - Fix kexec-tools' configure.ac.
 - Fix a few compilation warnings.

Size comparison of stripped binaries of kexec malta target with both
zlib and lzma support enabled.

 - Before: 41447
 - After:  42583

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@44437 3c298f89-4303-0410-b956-a3cf2f4a3e73