Swap the two CharDriverState arguments so that the first argument
corresponds to the channel A and the second argument to the channel B.

Modify hw/sun4m.c accordingly.

This fixes the order of the serial ports on the PPC machines.
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6284 c046a42c-6fe2-441c-8c8c-71466251a162