drm/i915/guc: Support OA when Wa_16011777198 is enabled

On DG2, a w/a resets RCS/CCS before it goes into RC6. This breaks OA
since OA does not expect engine resets during its use. Fix it by
disabling RC6.

v2: (Ashutosh)
- Bring back slpc_unset_param helper
- Update commit msg
- Use with_intel_runtime_pm helper for set/unset

v3: (Ashutosh)
- Just use intel_uc_uses_guc_rc

Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221026222102.5526-15-umesh.nerlige.ramappa@intel.com