rocr/aie: Correct reporting of dev heap size

Storing the correct dev heap size in the memory region.

Change-Id: I14b053330c187da1d7d0213256625e50795b9902

runtime/hsa-runtime/core/inc/amd_xdna_driver.h

@@ -63,6 +63,9 @@ public:
 
   static hsa_status_t DiscoverDriver();
 
+  /// @brief Returns the size of the dev heap in bytes.
+  static uint64_t GetDevHeapByteSize();
+
   hsa_status_t Init() override;
   hsa_status_t QueryKernelModeDriver(core::DriverQuery query) override;