drm/xe/xe2: Enable has_usm

When xe2 support started to be added, USM was still not functional. This
has changed, and now USM can be enabled for xe2. Remove FIXME leftover
to allow VM to be created with DRM_XE_VM_CREATE_FLAG_FAULT_MODE.
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240129214510.123829-1-lucas.demarchi@intel.com

drivers/gpu/drm/xe/xe_pci.c

@@ -165,7 +165,7 @@ static const struct xe_graphics_desc graphics_xelpg = {
 	.has_asid = 1, \
 	.has_flat_ccs = 1, \
 	.has_range_tlb_invalidation = 1, \
-	.has_usm = 0 /* FIXME: implementation missing */, \
+	.has_usm = 1, \
 	.va_bits = 48, \
 	.vm_max_level = 4, \
 	.hw_engine_mask = \