COMPMID-669 - Add validation for different border modes

- Box3x3
- Dilate
- Erode
- Gaussian 3x3
- Gaussian 5x5
- Median 3x3

Change-Id: I09a1a4c6fcdf62805626d73386ec56651bd40fb4
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/94862
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
diff --git a/tests/validation/fixtures/DilateFixture.h b/tests/validation/fixtures/DilateFixture.h
index 0b6fe2e..7b56cf6 100644
--- a/tests/validation/fixtures/DilateFixture.h
+++ b/tests/validation/fixtures/DilateFixture.h
@@ -52,8 +52,9 @@
         std::uniform_int_distribution<uint8_t> distribution(0, 255);
         const uint8_t                          constant_border_value = distribution(gen);
 
-        _target    = compute_target(shape, data_type, border_mode, constant_border_value);
-        _reference = compute_reference(shape, data_type, border_mode, constant_border_value);
+        _border_mode = border_mode;
+        _target      = compute_target(shape, data_type, border_mode, constant_border_value);
+        _reference   = compute_reference(shape, data_type, border_mode, constant_border_value);
     }
 
 protected: