[GPU] Integer abs support for activation

Author: kelvinchoi-intel

src/plugins/intel_gpu/src/graph/activation.cpp

@@ -26,7 +26,8 @@ layout activation_inst::calc_output_layout(activation_node const& node, kernel_i
         activation_func::negation,
         activation_func::relu,
         activation_func::floor,
-        activation_func::clamp };
+        activation_func::clamp,
+        activation_func::abs };
 
     if (input_node_layout.data_type == data_types::i8 || input_node_layout.data_type == data_types::u8 ||
         input_node_layout.data_type == data_types::i32) {

src/plugins/intel_gpu/tests/unit/test_cases/activation_simple_gpu_test.cpp

@@ -1579,7 +1579,8 @@ TEST(activation_i32_fw_gpu, basic_yxfb_i32_funcs) {
         activation_func::negation,
         activation_func::relu,
         activation_func::clamp,
-        activation_func::floor
+        activation_func::floor,
+        activation_func::abs
     };
 
     for (auto func : funcs) {
@@ -1620,6 +1621,9 @@ TEST(activation_i32_fw_gpu, basic_yxfb_i32_funcs) {
             case activation_func::floor:
                 ASSERT_EQ((int32_t)std::floor(input_ptr[i]), output_ptr[i]);
                 break;
+            case activation_func::abs:
+                ASSERT_EQ(std::abs(static_cast<int32_t>(input_ptr[i])), output_ptr[i]);
+                break;
             default:
                 break;
             }