lprng: fix QA issue for multilib

bitbake lprng
[snip]
ERROR: QA Issue: non debug package contains .debug directory: lprng path
/work/core2-64-poky-linux/lprng/3.8.C-r0/packages-split/lprng/usr/lib64/lprng/filters/.debug/lpf [debug-files]
[snip]

Signed-off-by: Yi Zhao <yi.zhao@windriver.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>