drm/i915/cnl: Add power wells for CNL

CNL power wells are very similar to SKL, with the exception that the
misc IO well has been split into separate AUX IO wells.

Not sure if DMC is supposed to manage the AUX wells for us or not.
Let's assume so for now.

v2: DDI A power well wants DDI A domains, not DDI B domains
v3: s/BIT/BIT_ULL and add proper Aux IO domains. (Rodrigo)
v4: Remove PW_DDI_E. Not supported on Current CNL SKUs. (Rodrigo).
v5: Removed DDI_E_IO_DOMAINS and moved PORT_DDI_E_IO to DDI_A_IO
    for the same reasons as v4 when we found out that current CNL
    SKUs don't have the full port E split.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1496781040-20888-10-git-send-email-rodrigo.vivi@intel.com