UARTs used to connect keyboards and not also PS/2 keyboards and only
return their package handle in case the keyboard is the preferred one
according to the OFW but otherwise still regardless of whether the
keyboard is used for stdin or not. This is simply achieved by looking
at the 'keyboard' alias and returning the corresponding package handle
in case it refers to a SCC/UART. This is change is done in order to
give the keyboard which the OFW or the user selected in OFW on boards
that support additional types of keyboards besides the RS232 ones also
preference in FreeBSD. It will be also used to determine on Sun AXi and
Sun AXmp boards whether a PS/2 or a RS232 is to be used as these are
sort of mutual exclusive there (see upcoming commit to uart_bus_ebus.c).
Note that Tatung AXi boards have the same issue but the former code
happened to already give the PS/2 keyboard preference by not identifying
the respective UART as keyboard system device there because the PS/2
keyboard node precedes the keyboard UART one in the OFW device tree of
these boards (which isn't the case for the Sun AXi).
Ok'ed by: marcel
aa557734c2