turnip/fuchsia: align sysmem allocations to height 4 Resolves MMU faults triggered by grafika's 456x197 allocations. Bug: 454700935 Change-Id: Ie4e2c967f3d284e35e0ae1fa60553950a5983453 Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/mesa/+/1583954 Commit-Queue: Craig Stout <cstout@google.com> Reviewed-by: David Gilhooley <dgilhooley@google.com>