FROMLIST: staging: vsoc: Fix a i386-randconfig warning.

Fix "warning: cast to pointer from integer of different size" when
printing the region shm physical address. Use the %pa conversion
specifier and pass the resource by reference.

Signed-off-by: Alistair Strachan <astrachan@google.com>
[sent upstream via staging TODO]
Bug: 702147120
Change-Id: Ibb0c32b461821235155c464bfd5c5963db512734