drm/i915/reset: remove I915_RESET_MODESET flag

drm/i915/reset: remove I915_RESET_MODESET flag

Since commit d59cf7bb73f3 ("drm/i915/display: Use dma_fence interfaces
instead of i915_sw_fence") we don't have anyone waiting on the
I915_RESET_MODESET bit, and there's no need for its semantics. Instead,
simply return true from intel_display_reset_prepare() to indicate that
intel_display_reset_finish() should be called.

Cc: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/294690db3fae8fec7f356edf467e79882ed494db.1741001054.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>