Merge pull request #25936 from savuor:rv/hal_dot

HAL for dot product added #25936

### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [x] The PR is proposed to the proper branch
- [ ] There is a reference to the original bug report and related work
- [ ] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [x] The feature is well documented and sample code can be built with the project CMake

modules/core/src/matmul.dispatch.cpp

@@ -995,9 +995,18 @@ double Mat::dot(InputArray _mat) const
     CV_INSTRUMENT_REGION();
 
     Mat mat = _mat.getMat();
+    CV_Assert_N( mat.type() == type(), mat.size == size);
+
     int cn = channels();
+    if (this->dims <= 2)
+    {
+        double product = 0;
+        CALL_HAL_RET(dotProduct, cv_hal_dotProduct, product, this->data, this->step, mat.data, mat.step,
+                     this->cols * cn, this->rows, this->depth());
+    }
+
     DotProdFunc func = getDotProdFunc(depth());
-    CV_Assert_N( mat.type() == type(), mat.size == size, func != 0 );
+    CV_Assert(func != 0 );
 
     if( isContinuous() && mat.isContinuous() )
     {