drm/i915/xe2lpd: remove the FBC restriction if PSR2 is enabled

In earlier versions, FBC was restricted if PSR2 is enabled. From
xe2lpd onwards no such restrictions are needed anymore.

HSD: 14014305387
Signed-off-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231110093225.39573-2-vinod.govindapillai@intel.com