Add fan presence support

Async montitor GPIO to get fan presence.

Tested-by: Pulled every fan on a 2U and monitored
presence.

Change-Id: Ibad2251e5c6a0ce480812051c103785f79fa60bb
Signed-off-by: James Feist <james.feist@linux.intel.com>
diff --git a/sensors/CMakeLists.txt b/sensors/CMakeLists.txt
index 55db096..a1c80e4 100644
--- a/sensors/CMakeLists.txt
+++ b/sensors/CMakeLists.txt
@@ -1,7 +1,7 @@
 cmake_minimum_required (VERSION 2.8.10 FATAL_ERROR)
 set (BUILD_SHARED_LIBRARIES OFF)
 include (ExternalProject)
-set (CMAKE_CXX_STANDARD 14)
+set (CMAKE_CXX_STANDARD 17)
 set (CMAKE_CXX_STANDARD_REQUIRED ON)
 set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -lstdc++fs")
 set (CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake ${CMAKE_MODULE_PATH})