feat(cmakev2/idf): add __git_init to identify the git executable

The Git tool will be used in various parts of the build system, such as
retrieving the IDF version using git-describe or checking submodules.
Similar to the Python interpreter, add an initialization function to
identify the Git executable.

Signed-off-by: Frantisek Hrbata <frantisek.hrbata@espressif.com>

tools/cmakev2/idf.cmake

@@ -49,6 +49,24 @@ function(__init_idf_path)
     set(ENV{IDF_PATH} ${idf_path})
 endfunction()
 
+#[[
+   __init_git()
+
+   Determine the executable.
+
+   Set the GIT build property.
+#]]
+function(__init_git)
+    find_package(Git)
+    if(NOT GIT_FOUND)
+        idf_build_set_property(GIT NOTFOUND)
+        idf_warn("Git executable not found.")
+        return()
+    endif()
+
+    idf_build_set_property(GIT "${GIT_EXECUTABLE}")
+endfunction()
+
 #[[
    __init_python()
 
@@ -332,6 +350,9 @@ idf_build_set_property(BUILD_DIR "${CMAKE_BINARY_DIR}")
 # well as a build property.
 __init_idf_path()
 
+# Determine git executable and set GIT build property.
+__init_git()
+
 # Determine the Python interpreter and check package dependencies if necessary.
 __init_python()