drm/i915/guc: More debug print updates - GuC SLPC

Update a bunch more debug prints to use the new GT based scheme.

v2: Also change prints to use %pe for error values (MichalW).

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230207050717.1833718-6-John.C.Harrison@Intel.com