powerpc/85xx: Cleanup QE initialization for MPC85xxMDS boards

The mpc85xx_mds_setup_arch() function is incomprehensible
and unmaintainable. Factor out all QE specific stuff into
mpc85xx_mds_qe_init() and mpc85xx_mds_reset_ucc_phys().

Also move QE stuff out of mpc85xx_mds_pic_init().

The diff is unreadable, but only because the code was so. ;-)
It should be better now, and less indented.

Signed-off-by: Anton Vorontsov <avorontsov@mvista.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>