drm/i915/guc: Connect reset modparam updates to GuC policy flags

Changing the reset module parameter has no effect on a running GuC.
The corresponding entry in the ADS must be updated and then the GuC
informed via a Host2GuC message.

The new debugfs interface to module parameters allows this to happen.
However, connecting the parameter data address back to anything useful
is messy. One option would be to pass a new private data structure
address through instead of just the parameter pointer. However, that
means having a new (and different) data structure for each parameter
and a new (and different) write function for each parameter. This
method keeps everything generic by instead using a string lookup on
the directory entry name.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210727002348.97202-22-matthew.brost@intel.com