no cleanwindows handler so just remove trying to trigger it from _start
and the AP trampoline code as that leads to a crash there. This should
be okay as leaking data from the OFW via the CPU registers on start of
the kernel should be no real concern.
- Make the comments of _start and the AP trampoline code regarding the
initializations they perform match each other and reality.
- Make the comments of the AP trampoline code regarding iTLB accesses
refer to the right macro.
dfade4c0a4