cmake: update to C++20

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I9060117746a8b13246656ff06baa091e98e09796
diff --git a/callback-manager/CMakeLists.txt b/callback-manager/CMakeLists.txt
index 16e184a..ae4d5e4 100644
--- a/callback-manager/CMakeLists.txt
+++ b/callback-manager/CMakeLists.txt
@@ -1,7 +1,7 @@
 cmake_minimum_required (VERSION 3.1 FATAL_ERROR)
 set (BUILD_SHARED_LIBRARIES OFF)
 include (ExternalProject)
-set (CMAKE_CXX_STANDARD 17)
+set (CMAKE_CXX_STANDARD 20)
 set (CMAKE_CXX_STANDARD_REQUIRED ON)
 set (CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake ${CMAKE_MODULE_PATH})
 set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-rtti")
diff --git a/hsbp-manager/CMakeLists.txt b/hsbp-manager/CMakeLists.txt
index 2b7d4f2..1556dab 100644
--- a/hsbp-manager/CMakeLists.txt
+++ b/hsbp-manager/CMakeLists.txt
@@ -1,7 +1,7 @@
 cmake_minimum_required (VERSION 3.1 FATAL_ERROR)
 set (BUILD_SHARED_LIBRARIES OFF)
 include (ExternalProject)
-set (CMAKE_CXX_STANDARD 17)
+set (CMAKE_CXX_STANDARD 20)
 set (CMAKE_CXX_STANDARD_REQUIRED ON)
 set (CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake ${CMAKE_MODULE_PATH})
 if (NOT YOCTO) # to download gtest