buildroot: Add systemd support for AV400. [3/3]

PD#SWPL-126048

Problem:
buildroot doesn't support systemd by default.

Solution:
Add systemd support in buildroot.

Verify:
AV400

Change-Id: Ieb02c188162fe6e92c66d3a6a7400d0765d2dfb6
Signed-off-by: hanliang.xiong <hanliang.xiong@amlogic.com>
1 file changed