drm/xe/pm: Disable D3Cold for BMG only on specific platforms

drm/xe/pm: Disable D3Cold for BMG only on specific platforms

Restrict D3Cold disablement for BMG to unsupported NUC platforms,
instead of disabling it on all platforms.

Signed-off-by: Karthik Poosa <karthik.poosa@intel.com>
Fixes: 3e331a6715ee ("drm/xe/pm: Temporarily disable D3Cold on BMG")
Link: https://patch.msgid.link/20260123173238.1642383-1-karthik.poosa@intel.com
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
(cherry picked from commit 39125eaf8863ab09d70c4b493f58639b08d5a897)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>