IVGCVSW-6073 Return Backend API Version to 1.0
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 <e59f6df1240b2b6c2b05aa682b1b9d01b9505720@arm.com>
Change-Id: I9c15bba29fe3b3258ae592e96889402f950b2a95

ARM-software/armnn,ARM-software/armnn,ARM-software/armnn