decompressors: add lz4 decompressor module

This patch adds support for LZ4 decompression in the kernel.
LZ4 Decompression APIs for kernel are based on LZ4 implementation
by Yann Collet.

LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html
LZ4 source repository : http://code.google.com/p/lz4/

Signed-off-by: Kyungsik Lee <kyungsik.lee@lge.com>
Signed-off-by: Seongmin Park <r_data@naver.com>
 lib: add support for LZ4-compressed kernels

This patch adds support for extracting LZ4-compressed kernel images,
as well as LZ4-compressed ramdisk images in the kernel boot process.

This depends on the patch below
decompressors: add lz4 decompressor module

Signed-off-by: Kyungsik Lee <kyungsik.lee@lge.com>
Signed-off-by: Seongmin Park <r_data@naver.com>
 arm: add support for LZ4-compressed kernels

This patch integrates the LZ4 decompression code to the arm pre-boot code.
And it depends on two patchs below

lib: add support for LZ4-compressed kernels
decompressors: add lz4 decompressor module

Signed-off-by: Kyungsik Lee <kyungsik.lee@lge.com>
Signed-off-by: Seongmin Park <r_data@naver.com>
Tested the LZ4 compress, but image is 11MB! we can have 8.2MB :(

i have donwloaded and compiled source of compress binary from here:
http://forum.xda-developers.com/showpost.php?p=39479147&postcount=71

Ubuntu X64 12.1 is here lib/lz4/lz4 need to copy to /bin/

nice to have, but not usable for us.
 timer: hrtimer: Don't check idle_cpu() before calling get_nohz_timer_…

…target()

Check for current cpu's idleness is already done in implementation of
sched_select_non_idle_cpu() which is called by get_nohz_timer_target(). So, no
need to call idle_cpu() twice, once from sched_select_non_idle_cpu() and once
from timer and hrtimer before calling get_nohz_timer_target().

This patch removes calls to idle_cpu() from timer and hrtimer.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Seongmin Park <r_data@naver.com>