drm/i915/icl: WaDisCtxReload

Revert to the legacy implementation to avoid a system hang.

v2: Correct the address for GAMW_ECO_DEV_RW_IA_REG
v3: Renamed to Wa_220166154
v4: Rebased on top of the WA refactoring
v5: Added References (Mika)
v6:
  - Rebased
  - C, not lisp (Chris)

References: HSDES#220166154
Signed-off-by: Oscar Mateo <oscar.mateo@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1525814984-20039-9-git-send-email-oscar.mateo@intel.com