IVGCVSW-6073 Return Backend API Version to 1.0

 * Backend API is still unstable and we shouldn't
   start to increment until we are ready, the change it was incremented
   in originally was also a major break due to the addition of
   a virtual method which would misalign the v-table.

Signed-off-by: Francis Murtagh <francis.murtagh@arm.com>
Change-Id: I9c15bba29fe3b3258ae592e96889402f950b2a95
diff --git a/include/armnn/backends/IBackendInternal.hpp b/include/armnn/backends/IBackendInternal.hpp
index 6267464..2045ba2 100644
--- a/include/armnn/backends/IBackendInternal.hpp
+++ b/include/armnn/backends/IBackendInternal.hpp
@@ -183,7 +183,7 @@
                                                MemorySourceFlags outputFlags);
 
     /// Returns the version of the Backend API
-    static constexpr BackendVersion GetApiVersion() { return BackendVersion(1, 1); }
+    static constexpr BackendVersion GetApiVersion() { return BackendVersion(1, 0); }
 
     /// Returns a BackendCapability if the backend lists the capability
     /// The BackendCapability must then be inspected to check whether or not that BackendCapability is supported