Hook up le(4) to the build. For now it's only added to the sparc64 GENERIC
in order to support the on-board LANCE in Ultra 1 and to the MI NOTES as
it should work just fine with the AMD PCnet family of chips on all archs
but is not yet meant to replace lnc(4). If a kernel includes all of le(4),
lnc(4) and pcn(4) precedence is given to lnc(4)/pcn(4) for now.