hal/imgproc: add hal for calcHist and implement in hal:riscv-rvv (#27332)

hal/imgproc: add hal for calcHist and implement in hal/riscv-rvv #27332

### Pull Request Readiness Checklist

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- [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.
- [ ] The feature is well documented and sample code can be built with the project CMake

modules/imgproc/src/hal_replacement.hpp

@@ -1395,6 +1395,26 @@ inline int hal_ni_polygonMoments(const uchar* src_data, size_t src_size, int src
 #define cv_hal_polygonMoments hal_ni_polygonMoments
 //! @endcond
 
+/**
+   @brief Calculates a histogram of a set of arrays
+   @param src_data Source imgage data
+   @param src_step Source image step
+   @param src_type Source image type
+   @param src_width Source image width
+   @param src_height Source image height
+   @param hist_data Histogram data
+   @param hist_size Histogram size
+   @param ranges Array of dims arrays of the histogram bin boundaries
+   @param uniform Flag indicating whether the histogram is uniform or not
+   @param accumulate Accumulation flag
+*/
+inline int hal_ni_calcHist(const uchar* src_data, size_t src_step, int src_type, int src_width, int src_height, float* hist_data, int hist_size, const float** ranges, bool uniform, bool accumulate)
+{ return CV_HAL_ERROR_NOT_IMPLEMENTED; }
+
+//! @cond IGNORED
+#define cv_hal_calcHist hal_ni_calcHist
+//! @endcond
+
 //! @}
 
 #if defined(__clang__)

modules/imgproc/src/histogram.cpp

@@ -978,6 +978,11 @@ void cv::calcHist( const Mat* images, int nimages, const int* channels,
             && _mask.empty() && images[0].dims <= 2 && ranges && ranges[0],
         ipp_calchist(images[0], hist, histSize[0], ranges, uniform, accumulate));
 
+    if (nimages == 1 && dims == 1 && channels && channels[0] == 0 && _mask.empty() && images[0].dims <= 2 && ranges && ranges[0]) {
+        CALL_HAL(calcHist, cv_hal_calcHist, images[0].data, images[0].step, images[0].type(), images[0].cols, images[0].rows,
+                                            hist.ptr<float>(), histSize[0], ranges, uniform, accumulate);
+    }
+
     Mat ihist = hist;
     ihist.flags = (ihist.flags & ~CV_MAT_TYPE_MASK)|CV_32S;