drm/xe/pm: Add scope-based cleanup helper for runtime PM

drm/xe/pm: Add scope-based cleanup helper for runtime PM

Add a scope-based helpers for runtime PM that may be used to simplify
cleanup logic and potentially avoid goto-based cleanup.

For example, using

        guard(xe_pm_runtime)(xe);

will get runtime PM and cause a corresponding put to occur automatically
when the current scope is exited.  'xe_pm_runtime_noresume' can be used
as a guard replacement for the corresponding 'noresume' variant.
There's also an xe_pm_runtime_ioctl conditional guard that can be used
as a replacement for xe_runtime_ioctl():

        ACQUIRE(xe_pm_runtime_ioctl, pm)(xe);
        if ((ret = ACQUIRE_ERR(xe_pm_runtime_ioctl, &pm)) < 0)
                /* failed */

In a few rare cases (such as gt_reset_worker()) we need to ensure that
runtime PM is dropped when the function is exited by any means
(including error paths), but the function does not need to acquire
runtime PM because that has already been done earlier by a different
function.  For these special cases, an 'xe_pm_runtime_release_only'
guard can be used to handle the release without doing an acquisition.

These guards will be used in future patches to eliminate some of our
goto-based cleanup.

v2:
 - Specify success condition for xe_pm runtime_ioctl as _RET >= 0 so
   that positive values will be properly identified as success and
   trigger destructor cleanup properly.

v3:
 - Add comments to the kerneldoc for the existing 'get' functions
   indicating that scope-based handling should be preferred where
   possible.  (Gustavo)

Cc: Gustavo Sousa <gustavo.sousa@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Gustavo Sousa <gustavo.sousa@intel.com>
Link: https://patch.msgid.link/20251118164338.3572146-31-matthew.d.roper@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>