fix(setup_board): Allow make.conf.user to be per-board
fix(setup_board): Allow make.conf.user to be per-board

Previously this would symlink to a global make.conf.user making it
impossible to apply changes to a board but not the SDK.

crawford/scripts,smilart/scripts,crawford/scripts,marineam/coreos-scripts,nicescale/scripts,marineam/coreos-scripts,fivethreeo/scripts,coreos/scripts,mischief/scripts,endocode/scripts,endocode/scripts,smilart/scripts,vmware/coreos-scripts,endocode/scripts,trnubo/scripts,fivethreeo/scripts,vmware/coreos-scripts,BugRoger/scripts,smilart/scripts,sigma/coreos-scripts,marineam/coreos-scripts,glevand/coreos--scripts,zhang0137/scripts,BugRoger/scripts,andrejro/coreos--scripts,nicescale/scripts,glevand/coreos--scripts,gtank/scripts,trnubo/scripts,mischief/scripts,sigma/coreos-scripts,zhang0137/scripts,BugRoger/scripts,mjg59/scripts,gtank/scripts,mjg59/scripts,mjg59/scripts,mischief/scripts,andrejro/coreos--scripts,sigma/coreos-scripts,andrejro/coreos--scripts,coreos/scripts,gtank/scripts,crawford/scripts,zhang0137/scripts,nicescale/scripts,fivethreeo/scripts,trnubo/scripts,vmware/coreos-scripts