cmake: find libudev library so it gets priority

cmake/sdlchecks.cmake

@@ -1139,3 +1139,16 @@ macro(CheckKMSDRM)
     endif()
   endif()
 endmacro()
+
+macro(CheckLibUDev)
+  if(SDL_LIBUDEV)
+    check_include_file("libudev.h" have_libudev_header)
+    if(have_libudev_header)
+      set(HAVE_LIBUDEV_H TRUE)
+      FindLibraryAndSONAME(udev)
+      if(UDEV_LIB_SONAME)
+        set(SDL_UDEV_DYNAMIC "\"${UDEV_LIB_SONAME}\"")
+      endif()
+    endif()
+  endif()
+endmacro()