added description for test

Author: dyniols

sycl/test-e2e/VirtualMem/memory_granularity.cpp

@@ -1,5 +1,9 @@
 // REQUIRES: aspect-ext_oneapi_virtual_mem
 
+// This test checks whether memory granularity returned is greater then 0 and 
+// that the recommended granularity is the same size or greater than the minimum 
+// granularity for virtul memory extension.
+
 // RUN: %{build} -o %t.out
 // RUN: %{run} %t.out