Build: Move test_ps_nv_counters into partition_ps

Instead of adding it to the sources of the ps test, as the file it
replaces is part of the ps partition.

Change-Id: Iedbcf94d90e7ebc6a9d54cd97fec181cde79207c
Signed-off-by: Raef Coles <raef.coles@arm.com>
1 file changed