drm/i915/tgl: Add memory type decoding for bandwidth checking

The memory type values have changed in TGL, so we need to translate them
differently than ICL. While we're moving it, fix up the ICL translation
for LPDDR4.

BSpec: 53998

v2: Fix up ICL LPDDR4 entry (Ville); Drop unused values from TGL (Ville)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Signed-off-by: James Ausmus <james.ausmus@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Stuart Summers <stuart.summers@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190924222829.13142-1-james.ausmus@intel.com