drm/i915/guc: Reset LRC descriptor if register returns -ENODEV

Reset LRC descriptor if a context register returns -ENODEV as this means
we are mid-reset.

Fixes: eb5e7da7 ("drm/i915/guc: Reset implementation for new GuC interface")
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210909164744.31249-15-matthew.brost@intel.com