drm/xe: Rename enable_display module param

drm/xe: Rename enable_display module param

The different approach used by xe regarding the initialization of
display HW has been proved a great addition for early driver bring up:
core xe can be tested without having all the bits sorted out on the
display side.

On the other hand, the approach exposed by i915-display is to *actively*
disable the display by programming it if needed, i.e. if it was left
enabled by firmware. It also has its use to make sure the HW is actually
disabled and not wasting power.

However having both the way it is in xe doesn't expose a good interface
wrt module params. From modinfo:

	disable_display:Disable display (default: false) (bool)
	enable_display:Enable display (bool)

Rename enable_display to probe_display to try to convey the message that
the HW is being touched and improve the module param description. To
avoid confusion, the enable_display is renamed everywhere, not only in
the module param. New description for the parameters:

	disable_display:Disable display (default: false) (bool)
	probe_display:Probe display HW, otherwise it's left untouched (default: true) (bool)

Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240813141931.3141395-1-lucas.demarchi@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>