when SSRAM regions are assigned to service VM
to support virtulization of SSRAM for post-launched
RTVMs, service VM need to access all SSRAM regions
for management, typically, service VM does data
cleanup in SSRAM region when it is reclaimed from
a shutdown RTVM.
This patch update memory type from UC(by default)
to WB, else SSARM region will be evicted when access
from guest happens.
Tracked-On: #7425
Signed-off-by: Yonghua Huang <yonghua.huang@intel.com>