Disable Solaris Graphic login

Often nvidia drivers could be a pain due to buggy driver code. This has
been a pain in snv_81/82. To just ignore the problem i had done the
following.

First reboot, edit during grub menu, and add -s argument to unix to boot
to single user mode.
Then perform the following command to disable cde-login, reboot again to
just get cmd line prompt for login.

#svcadm disable cde-login
#/usr/dt/bin/dtconfig -d