Fix GUI support with cmake 3.16
Updated cmakelist to fix gui support with cmake > 3.12.  Tested on ubuntu 18.04.
@@ -17,7 +17,7 @@ message(STATUS "Checking VPR graphics option ${ENABLE_VPR_GRAPHICS}")
if (ENABLE_VPR_GRAPHICS)
# check for dependencies
message(STATUS "VPR graphics is turned on, searching for dependencies")
- find_package(X11 COMPONENTS X11 Xft)
+ find_package(X11)
if (NOT X11_FOUND)
message(WARNING "Failed to find required X11 library (on debian/ubuntu try 'sudo apt-get install libx11-dev' to install)")
