lzop: Fix build using x32 ABI

When tries to build lzop using x32 ABI fails trying to get
FLAGS register that is 64-bit and destination variable is
32-bit size_t.

[YOCTO #7424]

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