maint(toolchain_util): Drop amd64-generic from list of valid boards.
maint(toolchain_util): Drop amd64-generic from list of valid boards.

The cleanup begins...

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