feat(build): add pkgconfig file (#4744)

Co-authored-by: Adam x Nilsson <adamni@axis.com>

env_support/cmake/custom.cmake

@@ -71,6 +71,12 @@ install(
   FILES_MATCHING
   PATTERN "*.h")
 
+configure_file("${LVGL_ROOT_DIR}/lvgl.pc.in" lvgl.pc @ONLY)
+
+install(
+  FILES "${CMAKE_BINARY_DIR}/lvgl.pc"
+  DESTINATION "${LIB_INSTALL_DIR}/pkgconfig/")
+
 set_target_properties(
   lvgl
   PROPERTIES OUTPUT_NAME lvgl

lvgl.pc.in

@@ -0,0 +1,10 @@
+prefix="@CMAKE_INSTALL_PREFIX@"
+includedir="${prefix}/@INC_INSTALL_DIR@"
+libdir=${prefix}/lib
+
+Name: lvgl
+Description: Light and Versatile Graphics Library
+URL: https://lvgl.io/
+Version: 9.0.0
+Cflags: -I${includedir}
+Libs: -L${libdir} -llvgl