Add patch to remove deprecated utime function.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

Decompression speedup of 7% on average.

Remove upstreamed uClibc-ng patch.

Fixed optimization option to show properly under menuconfig.

Added LTO for smaller size.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

uClibc-ng defines __GLIBCC__ and does not compile in execinfo.h. Disable
it.

Signed-off-by: Rosen Penev <rosenp@gmail.com>