drm/i915: Don't use WaGsvRC0ResidenncyMethod on chv

WaGsvRC0ResidenncyMethod is for vlv, it doesn't deal with chv
appropriately (eg. doesn't limit rps values to even numbers).

Fix a typo in the w/a name while at it.

Cc: Deepak S <deepak.s@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Deepak S <deepak.s@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>