Merge pull request #3845 from CodeLinaro:adsha_2ndPost

FastCV Extension code for OpenCV 2ndpost-2 #3845

### Description:
- Add support for cv::fastcv::calcHist

Depends on: [opencv/opencv_contrib#3844](https://github.com/opencv/opencv_contrib/pull/3844)
Depends on: [opencv/opencv#26619](https://github.com/opencv/opencv/pull/26619)
Requires binary from: [opencv/opencv_3rdparty#90](https://github.com/opencv/opencv_3rdparty/pull/90)

### 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
- [ ] 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/fastcv/include/opencv2/fastcv.hpp

@@ -16,6 +16,7 @@
 #include "opencv2/fastcv/edges.hpp"
 #include "opencv2/fastcv/fast10.hpp"
 #include "opencv2/fastcv/fft.hpp"
+#include "opencv2/fastcv/histogram.hpp"
 #include "opencv2/fastcv/hough.hpp"
 #include "opencv2/fastcv/ipptransform.hpp"
 #include "opencv2/fastcv/moments.hpp"

modules/fastcv/include/opencv2/fastcv/histogram.hpp

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+*/
+
+#ifndef OPENCV_FASTCV_HISTOGRAM_HPP
+#define OPENCV_FASTCV_HISTOGRAM_HPP
+
+#include <opencv2/core.hpp>
+
+namespace cv {
+namespace fastcv {
+
+//! @addtogroup fastcv
+//! @{
+
+/**
+ * @brief Calculates histogram of input image. This function implements specific use case of
+ *        256-bin histogram calculation for 8u single channel images in an optimized way.
+ * @param _src Intput image with type CV_8UC1
+ * @param _hist Output histogram of type int of 256 bins
+ */
+CV_EXPORTS_W void calcHist( InputArray _src, OutputArray _hist );
+//! @}
+
+} // fastcv::
+} // cv::
+
+#endif // OPENCV_FASTCV_HISTOGRAM_HPP

modules/fastcv/include/opencv2/fastcv/moments.hpp

@@ -16,7 +16,8 @@ namespace fastcv {
 
 /**
  * @brief Calculates all of the moments up to the third order of the image pixels' intensities
-          The results are returned in the structure cv::Moments.
+ *         The results are returned in the structure cv::Moments. This function cv::fastcv::moments()
+ *         calculate the moments using floating point calculations whereas cv::moments() calculate moments using double.
  * @param _src      Input image with type CV_8UC1, CV_32SC1, CV_32FC1
  * @param binary    If true, assumes the image to be binary (0x00 for black, 0xff for white), otherwise assumes the image to be
  *                  grayscale.